CVE-2025-8405

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CVE-2025-8405 GitLab vulnerability security vulnerability high severity CVE database GitLab CE GitLab EE unauthorized actions HTML injection

Summary

CVE-2025-8405 is a high-severity vulnerability affecting GitLab CE/EE. This vulnerability allows an authenticated user to perform unauthorized actions on behalf of other users by injecting malicious HTML into vulnerability code flow displays.

Successful exploitation could lead to privilege escalation and unauthorized access to sensitive data within the GitLab instance.

Technical Details

CVE-2025-8405 is a Cross-Site Scripting (XSS) vulnerability that arises from insufficient input sanitization within the vulnerability code flow displays in GitLab. An authenticated user with the ability to contribute to projects can inject malicious HTML code into specific fields related to vulnerabilities. When other users view these vulnerability displays, the injected HTML is executed within their browser context.

This allows the attacker to perform actions as the victim user, such as modifying data, accessing restricted resources, or even taking over their account. The vulnerability stems from the lack of proper encoding or escaping of user-supplied data before rendering it in the web interface.

Affected Products and Versions

  • GitLab CE/EE versions 17.1 before 18.4.6
  • GitLab CE/EE versions 18.5 before 18.5.4
  • GitLab CE/EE versions 18.6 before 18.6.2

Impact Assessment

Successful exploitation of CVE-2025-8405 can have significant consequences for GitLab users and organizations.

  • Account Takeover: An attacker can potentially take over the accounts of other users, including administrators, gaining full control over the GitLab instance.
  • Data Breach: Sensitive data stored within GitLab, such as source code, credentials, and configuration files, could be accessed and stolen.
  • Malicious Code Injection: The attacker could inject malicious code into projects, potentially compromising the security of applications built using GitLab.
  • Reputation Damage: A successful attack can damage the reputation of the organization using the vulnerable GitLab instance.

Remediation

Immediate Actions

  • Upgrade GitLab: Upgrade your GitLab CE/EE instance to the latest patched version (18.4.6, 18.5.4, or 18.6.2 or later).
  • Review User Permissions: Ensure that user permissions are appropriately configured to minimize the potential impact of a compromised account.

Long-term Solutions

  • Implement Input Sanitization: Ensure that all user-supplied data is properly sanitized and encoded before being displayed in the web interface.
  • Regular Security Audits: Conduct regular security audits of your GitLab instance to identify and address potential vulnerabilities.

References

Detection & Scanning

Detecting CVE-2025-8405 involves identifying vulnerable GitLab versions and analyzing network traffic for suspicious activity indicative of XSS attacks. Security scanners can be used to automatically identify vulnerable GitLab instances.

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