CVE-2026-77259 Vulnerability Analysis & Exploit Details

CVE-2026-77259
Vulnerability Scoring

7.7
/10
Very High Risk

Highly exploitable, CVE-2026-77259 poses a critical security risk that could lead to severe breaches.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: Low
    Some privileges are necessary to exploit the vulnerability.
  • Scope: Changed
    Successful exploitation can impact components beyond the vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2026-77259 Details

Status: Analyzed

Last updated: 🕐 29 Sep 2026, 13:03 UTC
Originally published on: 🕖 22 Sep 2026, 19:16 UTC

Time between publication and last update: 6 days

CVSS Release: version 3

CVSS3 Source

security-advisories@github.com

CVSS3 Type

Secondary

CVSS3 Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

CVE-2026-77259 Vulnerability Summary

CVE-2026-77259: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, confluence_upload_attachment opens a caller-selected server-local file without checking that the resolved path remains in the workspace. A caller can upload environment files, credentials, or other readable host data to a Confluence page and retrieve it through Atlassian. The advisory traces the vulnerable input and processing flow through confluence_upload_attachment, file_path, and open(file_path, "rb"), which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Assessing the Risk of CVE-2026-77259

Access Complexity Graph

The exploitability of CVE-2026-77259 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2026-77259

CVE-2026-77259 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2026-77259, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2026-77259, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: High
    Exploiting CVE-2026-77259 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: None
    CVE-2026-77259 poses no threat to data integrity.
  • Availability: None
    CVE-2026-77259 does not impact system availability.

CVE-2026-77259 References

External References

CWE Common Weakness Enumeration

CWE-552

CAPEC Common Attack Pattern Enumeration and Classification

  • Collect Data from Common Resource Locations CAPEC-150 An adversary exploits well-known locations for resources for the purposes of undermining the security of the target. In many, if not most systems, files and resources are organized in a default tree structure. This can be useful for adversaries because they often know where to look for resources or files that are necessary for attacks. Even when the precise location of a targeted resource may not be known, naming conventions may indicate a small area of the target machine's file tree where the resources are typically located. For example, configuration files are normally stored in the /etc director on Unix systems. Adversaries can take advantage of this to commit other types of attacks.
  • Probe System Files CAPEC-639 An adversary obtains unauthorized information due to improperly protected files. If an application stores sensitive information in a file that is not protected by proper access control, then an adversary can access the file and search for sensitive information.

Vulnerable Configurations

  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.6:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.6:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.7:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.7:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.8:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.8:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.9:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.9:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.10:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.10:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.11:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.11:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.12:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.12:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.13:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.13:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.14:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.14:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.15:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.15:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.16:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.16:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.6:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.6:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.3.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.3.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.3.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.3.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.4.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.4.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.5.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.5.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.7.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.7.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.7.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.7.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.9.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.9.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.6:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.6:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.6:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.6:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.7:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.7:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.8:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.8:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.9:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.9:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.10:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.10:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.11:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.11:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.12:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.12:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.12.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.12.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.13.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.13.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.13.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.13.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.15.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.15.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.16.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.16.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.16.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.16.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.17.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.17.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.18.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.18.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.18.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.18.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.19.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.19.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.20.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.20.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.20.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.20.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.21.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.21.0:*:*:*:*:*:*:*

Protect Your Infrastructure against CVE-2026-77259: Combat Critical CVE Threats

Stay updated with real-time CVE vulnerabilities and take action to secure your systems. Enhance your cybersecurity posture with the latest threat intelligence and mitigation techniques. Develop the skills necessary to defend against CVEs and secure critical infrastructures. Join the top cybersecurity professionals safeguarding today's infrastructures.

Other 5 Recently Published CVEs Vulnerabilities

  • CVE-2026-97318 – The Giveaways and Contests by RafflePress WordPress plugin before 1.12.27 does not properly validate a giveaway's parent page URL before saving it...
  • CVE-2026-97317 – The Giveaways and Contests by RafflePress WordPress plugin before 1.12.27 does not remove the reCAPTCHA secret key from the giveaway settings it e...
  • CVE-2026-94298 – The BuildKit WordPress plugin before 1.0.29 does not properly sanitise and escape data submitted by contributor-level users before storing it and ...
  • CVE-2026-92820 – The Ninja Forms - File Uploads plugin for WordPress is vulnerable to arbitrary file operations in all versions up to, and including, 3.3.34 via the...
  • CVE-2026-92174 – The SiteOrigin Widgets Bundle plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 1.73.2 via the 'them...