CVE-2026-1662
📋 TL;DR
An unauthenticated attacker can cause Denial of Service on GitLab instances by sending specially crafted requests to the Jira events endpoint. This affects all GitLab CE/EE installations running vulnerable versions, potentially making services unavailable to legitimate 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 users, requiring manual intervention to restore functionality.
Likely Case
Temporary service degradation or intermittent outages affecting user productivity.
If Mitigated
Minimal impact with proper rate limiting, WAF rules, and network segmentation in place.
🎯 Exploit Status
The vulnerability requires sending crafted requests but no authentication, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 18.7.5, 18.8.5, or 18.9.1
Vendor Advisory: https://about.gitlab.com/releases/2026/02/25/patch-release-gitlab-18-9-1-released/
Restart Required: Yes
Instructions:
1. Backup your GitLab instance. 2. Update to GitLab 18.7.5, 18.8.5, or 18.9.1 using your package manager. 3. Restart GitLab services. 4. Verify the update was successful.
🔧 Temporary Workarounds
Disable Jira Integration
linuxTemporarily disable Jira integration to remove the vulnerable endpoint.
gitlab-rails runner "ApplicationSetting.current.update!(jira_connect_application_key: nil)"
Implement Rate Limiting
linuxConfigure rate limiting on the Jira events endpoint to mitigate DoS attempts.
Add to /etc/gitlab/gitlab.rb: nginx['custom_gitlab_server_config'] = "location /api/v4/jira_connect/ { limit_req zone=gitlab_jira burst=5 nodelay; }"
🧯 If You Can't Patch
- Implement network-level controls to block or rate-limit requests to /api/v4/jira_connect/ endpoints.
- Deploy a WAF with rules to detect and block malicious patterns targeting the Jira events endpoint.
🔍 How to Verify
Check if Vulnerable:
Check GitLab version with: sudo gitlab-rake gitlab:env:info | grep 'Version:'Check Version:
sudo gitlab-rake gitlab:env:info | grep 'Version:'Verify Fix Applied:
Confirm version is 18.7.5, 18.8.5, or 18.9.1 or higher, and test Jira integration functionality.📡 Detection & Monitoring
Log Indicators:
- High volume of requests to /api/v4/jira_connect/ in GitLab logs
- Error logs showing request timeouts or resource exhaustion
Network Indicators:
- Unusual spike in traffic to GitLab Jira endpoints
- Multiple requests from single IPs to /api/v4/jira_connect/
SIEM Query:
source="gitlab" AND (url_path="/api/v4/jira_connect/" OR jira_connect) | stats count by src_ip