CVE-2025-6948
📋 TL;DR
This CVE describes a cross-site scripting (XSS) vulnerability in GitLab that allows attackers to inject malicious content. Under certain conditions, successful exploitation could enable attackers to perform actions on behalf of legitimate users. All GitLab CE/EE instances running affected versions are vulnerable.
💻 Affected Systems
- GitLab Community Edition
- GitLab Enterprise Edition
📦 What is this software?
Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →⚠️ Risk & Real-World Impact
Worst Case
Attackers could perform unauthorized actions as any user, potentially leading to data theft, account takeover, or complete system compromise.
Likely Case
Attackers could steal session tokens, perform limited unauthorized actions, or deface content through injected scripts.
If Mitigated
With proper input validation and output encoding, the impact would be limited to minor content manipulation.
🎯 Exploit Status
Exploitation requires specific conditions and user interaction. The HackerOne report suggests authenticated access may be needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 17.11.6, 18.0.4, 18.1.2
Vendor Advisory: https://gitlab.com/gitlab-org/gitlab/-/issues/552616
Restart Required: Yes
Instructions:
1. Backup your GitLab instance. 2. Update to patched version via package manager (apt/yum) or Docker. 3. Restart GitLab services. 4. Verify update with version check.
🔧 Temporary Workarounds
Content Security Policy (CSP)
allImplement strict CSP headers to limit script execution from untrusted sources.
Add CSP headers to nginx/Apache configuration
Input Validation Filter
allDeploy WAF or reverse proxy with XSS filtering rules.
Configure ModSecurity or similar WAF with XSS rules
🧯 If You Can't Patch
- Restrict user permissions to minimize impact of successful exploitation
- Implement network segmentation to isolate GitLab from sensitive systems
🔍 How to Verify
Check if Vulnerable:
Check GitLab version via admin panel or command: sudo gitlab-rake gitlab:env:infoCheck Version:
sudo gitlab-rake gitlab:env:info | grep VersionVerify Fix Applied:
Confirm version is 17.11.6+, 18.0.4+, or 18.1.2+ and test XSS payloads in user-controllable fields.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests with script tags
- Multiple failed login attempts followed by successful ones
- Unexpected user agent strings
Network Indicators:
- HTTP requests containing <script> tags in parameters
- Outbound connections to suspicious domains from GitLab server
SIEM Query:
source="gitlab" AND ("<script>" OR "javascript:" OR "onerror=" OR "onload=")