CVE-2025-0555

CVE-2025-0555 is a Cross-Site Scripting (XSS) vulnerability, classified under CWE-79, in GitLab Enterprise Edition (GitLab-EE). It affects all versions from 16.6 prior to 17.7.6, 17.8 prior to 17.8.4, and 17.9 prior to 17.9.1. Published on 2025-03-03, the flaw enables an attacker to bypass security controls and execute arbitrary scripts in a user's browser under specific conditions. The vulnerability carries a CVSS v3.1 base score of 7.7 (AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N), indicating high severity due to its potential for confidentially and integrity impacts.

An attacker requires low privileges (PR:L), such as access as a project member or similar role within the affected GitLab instance, to exploit this vulnerability over the network (AV:N). Exploitation demands high attack complexity (AC:H) and user interaction (UI:R), typically tricking a victim into performing an action like visiting a crafted page or interacting with malicious content. Upon success, the attack changes scope (S:C), allowing arbitrary script execution in the victim's browser, which can lead to high confidentiality (C:H) and integrity (I:H) impacts, such as session hijacking or data exfiltration, with no availability disruption (A:N).

Mitigation requires upgrading to patched GitLab-EE versions 17.7.6, 17.8.4, 17.9.1, or later. Additional details are available in the GitLab issue tracker at https://gitlab.com/gitlab-org/gitlab/-/issues/514004 and the HackerOne disclosure report at https://hackerone.com/reports/2939833.