CVE-2026-63118 Vulnerability Analysis & Exploit Details

CVE-2026-63118
Vulnerability Scoring

Analysis In Progress
Analysis In Progress

Attack Complexity Details

  • Attack Complexity:
    Attack Complexity Analysis In Progress
  • Attack Vector:
    Attack Vector Under Analysis
  • Privileges Required: None
    No authentication is required for exploitation.
  • Scope:
    Impact is confined to the initially vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2026-63118 Details

Status: Received on 29 Jul 2026, 20:17 UTC

Published on: 29 Jul 2026, 20:17 UTC

CVSS Release:

CVE-2026-63118 Vulnerability Summary

CVE-2026-63118: MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not validate the HTTP Host or Origin request headers, which allows a malicious browser page to use DNS rebinding to reach a locally running MCP server and invoke exposed tools. This issue is fixed in version 0.23.0.

Assessing the Risk of CVE-2026-63118

Access Complexity Graph

The exploitability of CVE-2026-63118 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-2026-63118

No exploitability data is available for CVE-2026-63118.

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-2026-63118, 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-2026-63118, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2026-63118 does not compromise confidentiality.
  • Integrity: None
    CVE-2026-63118 does not impact data integrity.
  • Availability: None
    CVE-2026-63118 does not affect system availability.

CVE-2026-63118 References

External References

CWE Common Weakness Enumeration

CWE-350

CAPEC Common Attack Pattern Enumeration and Classification

  • DNS Cache Poisoning CAPEC-142 A domain name server translates a domain name (such as www.example.com) into an IP address that Internet hosts use to contact Internet resources. An adversary modifies a public DNS cache to cause certain names to resolve to incorrect addresses that the adversary specifies. The result is that client applications that rely upon the targeted cache for domain name resolution will be directed not to the actual address of the specified domain name but to some other address. Adversaries can use this to herd clients to sites that install malware on the victim's computer or to masquerade as part of a Pharming attack.
  • DNS Rebinding CAPEC-275 An adversary serves content whose IP address is resolved by a DNS server that the adversary controls. After initial contact by a web browser (or similar client), the adversary changes the IP address to which its name resolves, to an address within the target organization that is not publicly accessible. This allows the web browser to examine this internal address on behalf of the adversary.
  • User-Controlled Filename CAPEC-73 An attack of this type involves an adversary inserting malicious characters (such as a XSS redirection) into a filename, directly or indirectly that is then used by the target software to generate HTML text or other potentially executable content. Many websites rely on user-generated content and dynamically build resources like files, filenames, and URL links directly from user supplied data. In this attack pattern, the attacker uploads code that can execute in the client browser and/or redirect the client browser to a site that the attacker owns. All XSS attack payload variants can be used to pass and exploit these vulnerabilities.
  • Pharming CAPEC-89 A pharming attack occurs when the victim is fooled into entering sensitive data into supposedly trusted locations, such as an online bank site or a trading platform. An attacker can impersonate these supposedly trusted sites and have the victim be directed to their site rather than the originally intended one. Pharming does not require script injection or clicking on malicious links for the attack to succeed.

Protect Your Infrastructure against CVE-2026-63118: 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-2026-67439 – OliveTin gives safe and simple access to predefined shell commands from a web interface. Prior to 3000.17.0, the service/internal/api/api.go StartA...
  • CVE-2026-67438 – OliveTin gives access to predefined shell commands from a web interface. From 3000.2.0 until 3000.17.0, the service/internal/executor/arguments.go ...
  • CVE-2026-67437 – OliveTin gives access to predefined shell commands from a web interface. From 3000.0.0 until 3000.17.0, the service/internal/auth/otoauth2/restapi_...
  • CVE-2026-65975 – Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. In versions 1.88.0 up to but not including 1.10...
  • CVE-2026-54249 – Pydantic AI is a Python agent framework for building Generative AI applications. In versions 1.65.0 through 1.105.0, and 2.0.0b1 through 2.0.0b5, a...