Focus on synacor vulnerabilities and metrics.
Last updated: 12 May 2026, 22:25 UTC
This page consolidates all known Common Vulnerabilities and Exposures (CVEs) associated with synacor. We track both calendar-based metrics (using fixed periods) and rolling metrics (using gliding windows) to give you a comprehensive view of security trends and risk evolution. Use these insights to assess risk and plan your patching strategy.
For a broader perspective on cybersecurity threats, explore the comprehensive list of CVEs by vendor and product. Stay updated on critical vulnerabilities affecting major software and hardware providers.
Total synacor CVEs: 85
Earliest CVE date: 23 Sep 2013, 20:55 UTC
Latest CVE date: 30 Mar 2026, 15:16 UTC
Latest CVE reference: CVE-2026-33373
30-day Count (Rolling): 0
365-day Count (Rolling): 10
Calendar-based Variation
Calendar-based Variation compares a fixed calendar period (e.g., this month versus the same month last year), while Rolling Growth Rate uses a continuous window (e.g., last 30 days versus the previous 30 days) to capture trends independent of calendar boundaries.
Month Variation (Calendar): -100.0%
Year Variation (Calendar): -28.57%
Month Growth Rate (30-day Rolling): -100.0%
Year Growth Rate (365-day Rolling): -28.57%
Average CVSS: 3.4
Max CVSS: 7.5
Critical CVEs (≥9): 0
| Range | Count |
|---|---|
| 0.0-3.9 | 33 |
| 4.0-6.9 | 47 |
| 7.0-8.9 | 7 |
| 9.0-10.0 | 0 |
These are the five CVEs with the highest CVSS scores for synacor, sorted by severity first and recency.
An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A Cross-Site Request Forgery (CSRF) vulnerability exists in Zimbra Web Client due to the issuance of authentication tokens without CSRF protection during certain account state transitions. Specifically, tokens generated after operations such as enabling two-factor authentication or changing a password may lack CSRF enforcement. While such a token is active, authenticated SOAP requests that trigger token generation or state changes can be performed without CSRF validation. An attacker could exploit this by inducing a victim to submit crafted requests, potentially allowing sensitive account actions such as disabling two-factor authentication. The issue is mitigated by ensuring CSRF protection is consistently enforced for all issued authentication tokens.
An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A cross-site request forgery (CSRF) vulnerability exists in Zimbra Webmail due to improper validation of CSRF tokens. The application accepts CSRF tokens supplied within the request body instead of requiring them through the expected request header. An attacker can exploit this issue by tricking an authenticated user into submitting a crafted request. This may allow unauthorized actions to be performed on behalf of the victim.
An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. An XML External Entity (XXE) vulnerability exists in the Zimbra Exchange Web Services (EWS) SOAP interface due to improper handling of XML input. An authenticated attacker can submit crafted XML data that is processed by an XML parser with external entity resolution enabled. Successful exploitation may allow disclosure of sensitive local files from the server.
An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Zimbra Briefcase feature due to insufficient sanitization of specific uploaded file types. When a user opens a publicly shared Briefcase file containing malicious scripts, the embedded JavaScript executes in the context of the user's session. This allows an attacker to run arbitrary scripts, potentially leading to data exfiltration or other unauthorized actions on behalf of the victim user.
Zimbra Collaboration (ZCS) 10.0 and 10.1 contains an LDAP injection vulnerability in the Mailbox SOAP service within a FolderAction operation. The application fails to properly sanitize user-supplied input before incorporating it into an LDAP search filter. An authenticated attacker can exploit this issue by sending a crafted SOAP request that manipulates the LDAP query, allowing retrieval of sensitive directory attributes.
Zimbra Collaboration Suite (ZCS) 10.0 and 10.1 contains a reflected cross-site scripting (XSS) vulnerability in the Classic Webmail REST interface (/h/rest). The application fails to properly sanitize user-supplied input, allowing an unauthenticated attacker to inject malicious JavaScript into a crafted URL. When a victim user accesses the link, the injected script executes in the context of the Zimbra webmail application, which could allow the attacker to perform actions on behalf of the victim.
Zimbra Collaboration (ZCS) 10 before 10.0.18 and 10.1 before 10.1.13 allows Classic UI stored XSS via Cascading Style Sheets (CSS) @import directives in an HTML e-mail message.
A Local File Inclusion (LFI) vulnerability exists in the Webmail Classic UI of Zimbra Collaboration (ZCS) 10.0 and 10.1 because of improper handling of user-supplied request parameters in the RestFilter servlet. An unauthenticated remote attacker can craft requests to the /h/rest endpoint to influence internal request dispatching, allowing inclusion of arbitrary files from the WebRoot directory.
An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0 and 10.0 and 10.1. A Cross-Site Scripting (XSS) vulnerability in the Zimbra Classic UI allows attackers to execute arbitrary JavaScript within the user's session, potentially leading to unauthorized access to sensitive information. This issue arises from insufficient sanitization of HTML content, specifically involving crafted tag structures and attribute values that include an @import directive and other script injection vectors. The vulnerability is triggered when a user views a crafted e-mail message in the Classic UI, requiring no additional user interaction.
An issue was discovered in Zimbra Collaboration (ZCS) 9.0.0 before Patch 43, 10.0.x before 10.0.12, 10.1.x before 10.1.4, and 8.8.15 before Patch 47. A Cross-Site Scripting (XSS) vulnerability in the Zimbra Classic UI allows attackers to execute arbitrary JavaScript within the user's session, potentially leading to unauthorized access to sensitive information. This issue arises from insufficient sanitization of HTML content, including malformed <img> tags with embedded JavaScript. The vulnerability is triggered when a user views a specially crafted email in the Classic UI, requiring no additional user interaction.
In Zimbra Collaboration (ZCS) 9.0 through 10.1, a Cross-Site Request Forgery (CSRF) vulnerability exists in the GraphQL endpoint (/service/extension/graphql) of Zimbra webmail due to a lack of CSRF token validation. This allows attackers to perform unauthorized GraphQL operations, such as modifying contacts, changing account settings, and accessing sensitive user data when an authenticated user visits a malicious website.
An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a <details> tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration.
SSRF vulnerability in the RSS feed parser in Zimbra Collaboration 9.0.0 before Patch 43, 10.0.x before 10.0.12, and 10.1.x before 10.1.4 allows unauthorized redirection to internal network endpoints.
SQL injection vulnerability in the ZimbraSync Service SOAP endpoint in Zimbra Collaboration 10.0.x before 10.0.12 and 10.1.x before 10.1.4 due to insufficient sanitization of a user-supplied parameter. Authenticated attackers can exploit this vulnerability by manipulating a specific parameter in the request, allowing them to inject arbitrary SQL queries that could retrieve email metadata.
An issue was discovered in the Webmail Classic UI in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A Local File Inclusion (LFI) vulnerability exists in the /h/rest endpoint, allowing authenticated remote attackers to include and access sensitive files in the WebRoot directory. Exploitation requires a valid auth token and involves crafting a malicious request targeting specific file paths.
An issue was discovered in Zimbra Collaboration (ZCS) through 10.1. A Cross-Site Scripting (XSS) vulnerability in the /h/rest endpoint of the Zimbra webmail and admin panel interfaces allows attackers to execute arbitrary JavaScript in the victim's session. This issue is caused by improper sanitization of user input, leading to potential compromise of sensitive information. Exploitation requires user interaction to access the malicious URL.
An issue was discovered in Zimbra Collaboration (ZCS) through 10.1. A stored Cross-Site Scripting (XSS) vulnerability exists in the /modern/contacts/print endpoint of Zimbra webmail. This allows an attacker to inject and execute arbitrary JavaScript code in the context of the victim's browser when a crafted vCard (VCF) file is processed and printed. This could lead to unauthorized actions within the victim's session.
In Zimbra Collaboration (ZCS) 9.0 and 10.0, a vulnerability in the Webmail Modern UI allows execution of stored Cross-Site Scripting (XSS) payloads. An attacker with administrative access to the Zimbra Administration Panel can inject malicious JavaScript code while configuring an email account. This injected code is stored on the server and executed in the context of the victim's browser when interacting with specific elements in the web interface. (The vulnerability can be mitigated by properly sanitizing input parameters to prevent the injection of malicious code.)
An issue was discovered in Zimbra Collaboration (ZCS) through v10.1. A Cross-Site Scripting (XSS) vulnerability exists in one of the endpoints of Zimbra Webmail due to insufficient sanitization of the packages parameter. Attackers can bypass the existing checks by using encoded characters, allowing the injection and execution of arbitrary JavaScript within a victim's session.
An issue was discovered in webmail in Zimbra Collaboration (ZCS) through 10.1. An attacker can exploit this vulnerability by creating a folder in the Briefcase module with a malicious payload and sharing it with a victim. When the victim interacts with the folder share notification, the malicious script executes in their browser. This stored Cross-Site Scripting (XSS) vulnerability can lead to unauthorized actions within the victim's session.
An issue was discovered in Zimbra Collaboration (ZCS) through 10.0. Zimbra Webmail (Modern UI) is vulnerable to a stored Cross-Site Scripting (XSS) attack due to improper sanitization of user input. This allows an attacker to inject malicious code into specific fields of an e-mail message. When the victim adds the attacker to their contacts, the malicious code is stored and executed when viewing the contact list. This can lead to unauthorized actions such as arbitrary mail sending, mailbox exfiltration, profile picture alteration, and other malicious actions. Proper sanitization and escaping of input fields are necessary to mitigate this vulnerability.
An issue was discovered in Zimbra Collaboration (ZCS) through 10.1. A reflected Cross-Site Scripting (XSS) issue exists through the Briefcase module due to improper sanitization of file content by the OnlyOffice formatter. This occurs when the victim opens a crafted URL pointing to a shared folder containing a malicious file uploaded by the attacker. The vulnerability allows the attacker to execute arbitrary JavaScript in the context of the victim's session.
A reflected Cross-Site Scripting (XSS) vulnerability has been identified in Zimbra Collaboration Suite (ZCS) 8.8.15, affecting one of the webmail calendar endpoints. This arises from improper handling of user-supplied input, allowing an attacker to inject malicious code that is reflected back in the HTML response.
The postjournal service in Zimbra Collaboration (ZCS) before 8.8.15 Patch 46, 9 before 9.0.0 Patch 41, 10 before 10.0.9, and 10.1 before 10.1.1 sometimes allows unauthenticated users to execute commands.
Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41 allows XSS in the Zimbra Classic Web Client.
Cross Site Scripting vulnerability in Zimbra ZCS v.8.8.15 allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.
Due to an issue with incorrect sudo permissions, Zimbra Collaboration Suite (ZCS) suffers from a local privilege escalation issue in versions 9.0.0 and prior, where the 'zimbra' user can effectively coerce postfix into running arbitrary commands as 'root'.
An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0. An attacker can upload arbitrary files through amavis via a cpio loophole (extraction to /opt/zimbra/jetty/webapps/zimbra/public) that can lead to incorrect access to any other user accounts. Zimbra recommends pax over cpio. Also, pax is in the prerequisites of Zimbra on Ubuntu; however, pax is no longer part of a default Red Hat installation after RHEL 6 (or CentOS 6). Once pax is installed, amavis automatically prefers it over cpio.
Zimbra Collaboration Suite (ZCS) 8.8.15 and 9.0 has mboximport functionality that receives a ZIP archive and extracts files from it. By bypassing authentication (i.e., not having an authtoken), an attacker can upload arbitrary files to the system, leading to directory traversal and remote code execution. NOTE: this issue exists because of an incomplete fix for CVE-2022-27925.
A reflected cross-site scripting (XSS) vulnerability in the /public/launchNewWindow.jsp component of Zimbra Collaboration (aka ZCS) 9.0 allows unauthenticated attackers to execute arbitrary web script or HTML via request parameters.
Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 has mboximport functionality that receives a ZIP archive and extracts files from it. An authenticated user with administrator rights has the ability to upload arbitrary files to the system, leading to directory traversal.
Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 allows an unauthenticated attacker to inject arbitrary memcache commands into a targeted instance. These memcache commands becomes unescaped, causing an overwrite of arbitrary cached entries.
An issue was discovered in the Calendar feature in Zimbra Collaboration Suite 8.8.x before 8.8.15 patch 30 (update 1), as exploited in the wild starting in December 2021. An attacker could place HTML containing executable JavaScript inside element attributes. This markup becomes unescaped, causing arbitrary markup to be injected into the document.
An issue in /domain/service/.ewell-known/caldav of Zimbra Collaboration 8.8.12 allows attackers to redirect users to any arbitrary website of their choosing.
A reflected cross-site scripting (XSS) vulnerability in the zimbraAdmin/public/secureRequest.jsp component of Zimbra Collaboration 8.8.12 allows unauthenticated attackers to execute arbitrary web scripts or HTML via a host header injection.
An XSS vulnerability exists in the Webmail component of Zimbra Collaboration Suite before 8.8.15 Patch 11. It allows an attacker to inject executable JavaScript into the account name of a user's profile. The injected code can be reflected and executed when changing an e-mail signature.
Zimbra before 8.8.15 Patch 10 and 9.x before 9.0.0 Patch 3 allows remote code execution via an avatar file. There is potential abuse of /service/upload servlet in the webmail subsystem. A user can upload executable files (exe,sh,bat,jar) in the Contact section of the mailbox as an avatar image for a contact. A user will receive a "Corrupt File" error, but the file is still uploaded and stored locally in /opt/zimbra/data/tmp/upload/, leaving it open to possible remote execution.
An issue was discovered in Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7. When grantors revoked a shared calendar in Outlook, the calendar stayed mounted and accessible.
Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled.
Zimbra Collaboration before 8.8.12 Patch 1 has persistent XSS.
Zimbra Collaboration before 8.6.0 patch5 has XSS.
Synacor Zimbra Collaboration before 8.0.9 allows plaintext command injection during STARTTLS.
Synacor Zimbra Collaboration before 8.0.8 has XSS.
Synacor Zimbra Mail Client 8.6 before 8.6.0 Patch 5 has XSS via the error/warning dialog and email body content in Zimbra.
Synacor Zimbra Collaboration Server 8.x before 8.7.0 has Reflected XSS in admin console.
There is a Persistent XSS vulnerability in the briefcase component of Synacor Zimbra Collaboration Suite (ZCS) Zimbra Web Client (ZWC) 8.8.8 before 8.8.8 Patch 7 and 8.8.9 before 8.8.9 Patch 1.
Synacor Zimbra Admin UI in Zimbra Collaboration Suite before 8.8.0 beta 2 has Persistent XSS via mail addrs.
An issue was discovered in Synacor Zimbra Collaboration Suite 8.6.x before 8.6.0 Patch 11, 8.7.x before 8.7.11 Patch 6, 8.8.x before 8.8.8 Patch 9, and 8.8.9 before 8.8.9 Patch 3. Account number enumeration is possible via inconsistent responses for specific types of authentication requests.
mailboxd component in Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10 has an XML External Entity injection (XXE) vulnerability, as demonstrated by Autodiscover/Autodiscover.xml.
Zimbra Collaboration Suite 8.7.x through 8.8.11 allows Blind SSRF in the Feed component.
Synacor Zimbra Collaboration Suite 8.7.x through 8.8.11 allows insecure object deserialization in the IMAP component.
ZxChat (aka ZeXtras Chat), as used for zimbra-chat and zimbra-talk in Synacor Zimbra Collaboration Suite 8.7 and 8.8 and in other products, allows XXE attacks, as demonstrated by a crafted XML request to mailboxd.
mailboxd component in Synacor Zimbra Collaboration Suite 8.6, 8.7 before 8.7.11 Patch 7, and 8.8 before 8.8.10 Patch 2 has Persistent XSS.
Synacor Zimbra Collaboration Suite Collaboration before 8.8.11 has XSS in the AJAX and html web clients.
Zimbra Collaboration Suite before 8.6 patch 13, 8.7.x before 8.7.11 patch 10, and 8.8.x before 8.8.10 patch 7 or 8.8.x before 8.8.11 patch 3 allows SSRF via the ProxyServlet component.
Zimbra Collaboration before 8.8.10 GA allows text content spoofing via a loginErrorCode value.
Zimbra Web Client (ZWC) in Zimbra Collaboration Suite 8.8 before 8.8.8.Patch4 and 8.7 before 8.7.11.Patch4 has Persistent XSS via a contact group.
Cross-site request forgery (CSRF) vulnerability in the login form in Zimbra Collaboration Suite (aka ZCS) before 8.6.0 Patch 10, 8.7.x before 8.7.11 Patch 2, and 8.8.x before 8.8.8 Patch 1 allows remote attackers to hijack the authentication of unspecified victims by leveraging failure to use a CSRF token.
mailboxd in Zimbra Collaboration Suite 8.8 before 8.8.8; 8.7 before 8.7.11.Patch3; and 8.6 before 8.6.0.Patch10 allows zimbraSSLPrivateKey read access via a GetServer, GetAllServers, or GetAllActiveServers call in the Admin SOAP API.
mailboxd in Zimbra Collaboration Suite 8.8 before 8.8.8; 8.7 before 8.7.11.Patch3; and 8.6 before 8.6.0.Patch10 allows Information Exposure through Verbose Error Messages containing a stack dump, tracing data, or full user-context dump.
mailboxd in Zimbra Collaboration Suite 8.8 before 8.8.8; 8.7 before 8.7.11.Patch3; and 8.6 allows Account Enumeration by leveraging a Discrepancy between the "HTTP 404 - account is not active" and "HTTP 401 - must authenticate" errors.
Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachmentLinkHtml function in Zimbra Collaboration Suite (ZCS) before 8.7 Patch 1 and 8.8.x before 8.8.7 might allow remote attackers to inject arbitrary web script or HTML via a Content-Location header in an email attachment.
Synacor Zimbra Collaboration Suite (ZCS) before 8.7.10 has Persistent XSS.
Synacor Zimbra Collaboration Suite (ZCS) before 8.8.3 has Persistent XSS.
Cross-site scripting (XSS) vulnerability in Zimbra Collaboration Suite (ZCS) before 8.7.1 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
Directory traversal vulnerability in Zimbra Collaboration Suite (aka ZCS) before 8.7.6 allows attackers to have unspecified impact via unknown vectors.
A service provided by Zimbra Collaboration Suite (ZCS) before 8.7.6 fails to require needed privileges before performing a few requested operations.
Multiple cross-site request forgery (CSRF) vulnerabilities in the Admin Console in Zimbra Collaboration before 8.6.0 Patch 8 allow remote attackers to hijack the authentication of administrators for requests that (1) add, (2) modify, or (3) remove accounts by leveraging failure to use of a CSRF token and perform referer header checks, aka bugs 100885 and 100899.
Zimbra Collaboration Suite (ZCS) before 8.7.4 allows remote attackers to conduct XML External Entity (XXE) attacks.
Unspecified vulnerability in Zimbra Collaboration before 8.7.0 allows remote attackers to affect integrity via unknown vectors, aka bug 104477.
Multiple cross-site scripting (XSS) vulnerabilities in Zimbra Collaboration before 8.7.0 allow remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka bugs 104552 and 104703.
Zimbra Collaboration before 8.7.0 allows remote attackers to conduct deserialization attacks via unspecified vectors, aka bug 102276.
Unspecified vulnerability in Zimbra Collaboration before 8.6.0 Patch 7 allows remote authenticated users to affect availability via unknown vectors, aka bug 102029.
Unspecified vulnerability in Zimbra Collaboration before 8.7.0 allows remote attackers to affect integrity via unknown vectors, aka bug 103996.
Multiple cross-site scripting (XSS) vulnerabilities in Zimbra Collaboration before 8.7.0 allow remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka bugs 103997, 104413, 104414, 104777, and 104791.
Cross-site scripting (XSS) vulnerability in Zimbra Collaboration before 8.7.0 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka bug 103609.
Multiple cross-site scripting (XSS) vulnerabilities in Zimbra Collaboration before 8.7.0 allow remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka bugs 103956, 103995, 104475, 104838, and 104839.
Cross-site scripting (XSS) vulnerability in Zimbra Collaboration before 8.7.0 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka bug 102637.
Cross-site scripting (XSS) vulnerability in Zimbra Collaboration before 8.7.0 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka bug 101813.
Multiple cross-site scripting (XSS) vulnerabilities in Zimbra Collaboration before 8.7.0 allow remote attackers to inject arbitrary web script or HTML via unspecified vectors, aka bugs 104222, 104910, 105071, and 105175.
Multiple cross-site request forgery (CSRF) vulnerabilities in Zimbra Collaboration before 8.7.0 allow remote attackers to hijack the authentication of unspecified victims via vectors involving (1) the Client uploader extension or (2) extension REST handlers, aka bugs 104294 and 104456.
Multiple unspecified vulnerabilities in Zimbra Collaboration before 8.7.0 allow remote attackers to affect integrity via unknown vectors, aka bugs 103961 and 104828.
Unspecified vulnerability in Zimbra Collaboration before 8.7.0 allows remote attackers to affect integrity via unknown vectors, aka bug 103959.
Unspecified vulnerability in Zimbra Collaboration before 8.7.0 allows remote attackers to affect confidentiality via unknown vectors, aka bug 99167.
Unspecified vulnerability in Zimbra Collaboration before 8.7.0 allows remote authenticated users to affect integrity via unknown vectors, aka bug 99810.
Directory traversal vulnerability in /res/I18nMsg,AjxMsg,ZMsg,ZmMsg,AjxKeys,ZmKeys,ZdMsg,Ajx%20TemplateMsg.js.zgz in Zimbra 7.2.2 and 8.0.2 allows remote attackers to read arbitrary files via a .. (dot dot) in the skin parameter. NOTE: this can be leveraged to execute arbitrary code by obtaining LDAP credentials and accessing the service/admin/soap API.
Zimbra Collaboration Suite (ZCS) 6.0.16 and earlier allows man-in-the-middle attackers to obtain access by sniffing the network and replaying the ZM_AUTH_TOKEN token.