CVE-2025-9642 in Community Edition
Summary
by MITRE • 09/26/2025
An issue has been discovered in GitLab CE/EE affecting all versions from 14.10 before 18.2.7, 18.3 before 18.3.3, and 18.4 before 18.4.1 that could allow an attacker to inject malicious content that may lead to account takeover.
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Analysis
by VulDB Data Team • 09/30/2025
The vulnerability identified as CVE-2025-9642 represents a critical security flaw in GitLab Community Edition and Enterprise Edition platforms that has persisted across multiple version ranges. This issue stems from inadequate input validation mechanisms within the application's content handling processes, creating a pathway for malicious actors to inject unauthorized content into the system. The vulnerability affects versions from 14.10 through 18.2.6, 18.3 through 18.3.2, and 18.4 through 18.4.0, indicating a widespread impact across several major release lines. The flaw resides in the platform's content sanitization and validation routines that fail to properly filter or escape user-supplied data before processing or storage.
The technical implementation of this vulnerability allows attackers to exploit weaknesses in the input sanitization pipeline where user-provided content undergoes insufficient validation before being processed by the application's core systems. This particular flaw manifests when the system fails to properly sanitize or escape special characters and script tags that could be embedded within user-generated content. The vulnerability can be categorized under CWE-79, which specifically addresses Cross-Site Scripting (XSS) flaws in software applications. Attackers can leverage this weakness to inject malicious scripts that execute within the context of other users' browsers, potentially leading to session hijacking and unauthorized access to sensitive data. The attack vector typically involves crafting specially formatted content that bypasses existing security controls and gets stored within the GitLab instance.
The operational impact of CVE-2025-9642 extends beyond simple data corruption or display issues, as it creates a direct pathway for account takeover and persistent unauthorized access to GitLab environments. When successful, this vulnerability enables attackers to execute arbitrary code within the context of legitimate user sessions, potentially allowing them to escalate privileges, access confidential repositories, and manipulate codebases. The attack could result in complete compromise of development environments, exposure of source code, and unauthorized modifications to critical infrastructure. This vulnerability particularly affects organizations relying on GitLab for source code management, CI/CD pipelines, and collaborative development environments where unauthorized access could lead to significant business disruption and data breaches. The potential for persistent access through session manipulation creates a long-term security risk that could remain undetected for extended periods.
Organizations should immediately implement mitigations including updating to the patched versions 18.2.7, 18.3.3, and 18.4.1 respectively, as these releases contain the necessary patches to address the input validation weaknesses. System administrators should also consider implementing additional defensive measures such as enhanced content filtering, web application firewalls, and monitoring for suspicious content injection attempts. The vulnerability aligns with ATT&CK technique T1566, which covers credential access through social engineering and content injection methods. Security teams should conduct comprehensive vulnerability assessments to identify any potential exploitation attempts that may have occurred prior to patching, while also reviewing access logs and user activity for signs of unauthorized access. Organizations utilizing GitLab should also implement principle of least privilege access controls and regular security audits to minimize the potential impact of such vulnerabilities in their environments.