{"id":85894,"date":"2025-11-26T12:28:19","date_gmt":"2025-11-26T12:28:19","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T00:00:00","slug":"cve-2025-4439-gitlab-ce-ee-xss-vulnerability-through-certain-cdns","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-4439-gitlab-ce-ee-xss-vulnerability-through-certain-cdns\/","title":{"rendered":"CVE-2025-4439: GitLab CE\/EE XSS Vulnerability Through Certain CDNs<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

This report discusses the details of a discovered vulnerability, CVE-2025-4439, found in GitLab CE\/EE versions ranging from 15.10 to 18.2.1. This vulnerability presents a significant risk as it allows an authenticated user to perform cross-site scripting (XSS) attacks when the instance is served through certain content delivery networks (CDNs). Given the widespread use of GitLab for version control and project management, it is crucial for organizations to understand and mitigate this risk.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-4439
\nSeverity: High (7.7 CVSS Score)
\nAttack Vector: Network
\nPrivileges Required: Low
\nUser Interaction: Required
\nImpact: Potential system compromise or data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

GitLab CE\/EE | 15.10 – 18.0.4
\nGitLab CE\/EE | 18.1 – 18.1.2
\nGitLab CE\/EE | 18.2 – 18.2.0<\/p>\n

How the Exploit Works<\/strong><\/p>\n

CVE-2025-4439 exploits a flaw in the handling of certain CDNs by the GitLab instance. An authenticated user can inject malicious scripts into the web application, which are then executed in the user’s browser when they access the web app through the affected CDNs. This is a classic Cross-Site Scripting attack, a common web security vulnerability.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

POST \/vulnerable\/cdn HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\n{\n\"script\": \"<script>malicious_code_here<\/script>\"\n}<\/code><\/pre>\n
This is a conceptual example demonstrating how the payload with malicious script might be sent to the vulnerable endpoint.<\/p>\n
Mitigation Guidance<\/strong><\/p>\n
To mitigate this vulnerability, users are advised to immediately apply the vendor patch when available. As a temporary mitigation, users can employ Web Application Firewalls (WAFs) or Intrusion Detection Systems (IDS) to detect and prevent exploitation of this vulnerability.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview This report discusses the details of a discovered vulnerability, CVE-2025-4439, found in GitLab CE\/EE versions ranging from 15.10 to 18.2.1. This vulnerability presents a significant risk as it allows an authenticated user to perform cross-site scripting (XSS) attacks when the instance is served through certain content delivery networks (CDNs). Given the widespread use of […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-85894","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t