CVE-2025-13761 in Community Edition
Summary
by MITRE • 01/09/2026
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.6 before 18.6.3, and 18.7 before 18.7.1 that could have allowed an unauthenticated user to execute arbitrary code in the context of an authenticated user's browser by convincing the legitimate user to visit a specially crafted webpage.
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Analysis
by VulDB Data Team • 02/15/2026
This vulnerability represents a critical cross-site scripting flaw that enables remote code execution through social engineering attacks targeting authenticated users. The issue affects GitLab Community and Enterprise editions across specific version ranges, creating a dangerous attack surface where unauthenticated adversaries can manipulate authenticated users into executing malicious code within their browser context. The vulnerability stems from insufficient input validation and output encoding mechanisms that fail to properly sanitize user-controllable data in web responses. Attackers can craft malicious web pages that, when visited by authenticated users, trigger code execution in the victim's browser session. This type of vulnerability falls under the CWE-79 category for cross-site scripting, specifically representing a stored or reflected XSS attack vector that can be escalated to arbitrary code execution. The attack requires user interaction through social engineering tactics where victims must be convinced to visit the malicious webpage, making it particularly challenging to detect and prevent through automated means.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking, as it allows attackers to execute arbitrary commands within the authenticated user's browser environment. This creates a significant risk for organizations relying on GitLab for code repository management, CI/CD pipelines, and collaborative development workflows. The exploitation process typically involves crafting malicious URLs or embedded content that triggers JavaScript execution when rendered in the victim's browser. The vulnerability's severity is amplified by the fact that it operates within the context of authenticated users, potentially granting attackers access to sensitive repositories, code modifications, and administrative functions. Organizations using affected GitLab versions face increased risk of data breaches, code injection attacks, and potential lateral movement within their development environments. This vulnerability aligns with ATT&CK technique T1566 for social engineering and T1059 for command and script injection, demonstrating how web-based attacks can escalate to full system compromise when combined with user interaction.
The remediation process requires immediate patching of affected GitLab installations to versions 18.6.3 and 18.7.1 or later, as these releases contain the necessary security fixes for input validation and output encoding. Organizations should implement comprehensive monitoring for suspicious user behavior and web traffic patterns that might indicate exploitation attempts. Security teams should conduct thorough vulnerability assessments of their GitLab installations and review access controls to minimize potential impact. Network segmentation and web application firewalls can provide additional defense-in-depth layers, though the primary mitigation remains timely patching. The vulnerability highlights the importance of maintaining up-to-date software versions and implementing robust input validation practices throughout the application lifecycle. Organizations should also consider implementing user education programs to reduce susceptibility to social engineering attacks that leverage this vulnerability. Regular security audits and penetration testing should be conducted to identify similar weaknesses in other web applications and systems. The incident underscores the critical need for continuous security monitoring and rapid response capabilities when dealing with browser-based exploits that can be leveraged for arbitrary code execution.