CVE-2025-5996
📋 TL;DR
This vulnerability in GitLab CE/EE allows authenticated users to cause denial of service through improper input validation in HTTP responses. It affects all GitLab instances running vulnerable versions, potentially disrupting service availability for all users.
💻 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
Complete service unavailability for all GitLab users, disrupting code repositories, CI/CD pipelines, and collaboration tools.
Likely Case
Partial service degradation or temporary outages affecting specific GitLab components or users.
If Mitigated
Minimal impact with proper authentication controls and monitoring in place to detect and block exploitation attempts.
🎯 Exploit Status
Requires authenticated access; exploitation details not publicly disclosed
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 17.10.8, 17.11.4, or 18.0.2
Vendor Advisory: https://gitlab.com/gitlab-org/gitlab/-/issues/476671
Restart Required: Yes
Instructions:
1. Backup your GitLab instance. 2. Update to GitLab 17.10.8, 17.11.4, or 18.0.2 using your package manager. 3. Restart GitLab services. 4. Verify the update completed successfully.
🔧 Temporary Workarounds
Restrict User Access
allLimit authenticated user accounts to only trusted personnel
Rate Limiting
allImplement rate limiting on HTTP endpoints to reduce DoS impact
🧯 If You Can't Patch
- Implement strict authentication controls and monitor for suspicious user activity
- Deploy network-level protections like WAF rules to detect and block DoS patterns
🔍 How to Verify
Check if Vulnerable:
Check GitLab version via Admin Area or command line; compare against affected versionsCheck Version:
sudo gitlab-rake gitlab:env:info | grep VersionVerify Fix Applied:
Verify GitLab version is 17.10.8, 17.11.4, or 18.0.2 or later📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP response patterns
- Multiple failed requests from single authenticated users
- Service degradation logs
Network Indicators:
- Spike in HTTP traffic from authenticated sessions
- Abnormal response times
SIEM Query:
source="gitlab" AND (http_status=5xx OR response_time>threshold) AND user_authenticated=true