CVE-2026-1069: GitLab CE/EE DoS Vulnerability

CVE-2026-1069 Overview

CVE-2026-1069 is a denial of service vulnerability affecting GitLab Community Edition (CE) and Enterprise Edition (EE). The vulnerability exists in the GraphQL API endpoint, where an unauthenticated attacker can cause service disruption by sending specially crafted GraphQL requests that trigger uncontrolled recursion under certain circumstances. This vulnerability is classified under CWE-674 (Uncontrolled Recursion).

Critical Impact

Unauthenticated attackers can remotely cause denial of service conditions on GitLab instances, potentially disrupting development workflows and CI/CD pipelines for entire organizations.

Affected Products

• GitLab Community Edition (CE) versions 18.9 before 18.9.2
• GitLab Enterprise Edition (EE) versions 18.9 before 18.9.2

Discovery Timeline

• 2026-03-11 - GitLab releases security patch version 18.9.2
• 2026-03-11 - CVE-2026-1069 published to NVD
• 2026-03-12 - Last updated in NVD database

Technical Details for CVE-2026-1069

Vulnerability Analysis

This vulnerability resides in GitLab's GraphQL API implementation. GraphQL's flexible query language allows clients to define the structure of responses, including nested queries. When certain GraphQL queries are constructed with deep or circular nesting patterns, the server-side query resolver fails to properly limit recursion depth, leading to stack exhaustion or excessive resource consumption.

The attack can be executed without authentication, as the vulnerable GraphQL endpoint is publicly accessible on affected GitLab instances. This significantly increases the risk exposure, as any internet-facing GitLab installation running vulnerable versions could be targeted.

Root Cause

The vulnerability stems from CWE-674: Uncontrolled Recursion. The GitLab GraphQL resolver does not adequately enforce limits on query depth or complexity when processing certain types of nested queries. When a malicious query with recursive relationships is submitted, the server attempts to resolve all nested levels without proper termination conditions, eventually exhausting available resources.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker can craft a malicious GraphQL query with deeply nested or circular references and submit it to the /api/graphql endpoint. The server processes this query without adequate recursion limits, causing resource exhaustion that leads to service unavailability.

The exploitation involves sending HTTP POST requests to the GraphQL endpoint with queries designed to maximize recursion depth. Due to the unauthenticated nature of this attack surface, any network-connected adversary can trigger the denial of service condition.

Detection Methods for CVE-2026-1069

Indicators of Compromise

• Unusual spike in GraphQL API requests from single or distributed sources
• Server resource exhaustion symptoms (high CPU, memory usage, or stack overflow errors)
• GitLab application logs showing deep query processing or recursion-related errors
• Service availability issues or timeouts on GitLab web interface and API endpoints

Detection Strategies

• Monitor GraphQL endpoint (/api/graphql) for abnormal request patterns or query complexity
• Implement rate limiting and query complexity analysis on the GraphQL API
• Configure alerting for sudden increases in server resource utilization
• Review application logs for stack overflow exceptions or recursion depth warnings

Monitoring Recommendations

• Enable detailed logging for GraphQL query processing to identify potentially malicious queries
• Set up real-time monitoring for GitLab service availability and response times
• Implement network-level monitoring to detect high-volume requests targeting the GraphQL endpoint
• Configure automated alerts for abnormal patterns in API request rates or resource consumption

How to Mitigate CVE-2026-1069

Immediate Actions Required

• Upgrade GitLab CE/EE to version 18.9.2 or later immediately
• If immediate patching is not possible, consider temporarily restricting access to the GraphQL API endpoint
• Review access logs for potential exploitation attempts prior to patching
• Implement Web Application Firewall (WAF) rules to limit GraphQL query depth and complexity

Patch Information

GitLab has released version 18.9.2 which addresses this vulnerability. The patch implements proper recursion depth limits and query complexity analysis in the GraphQL resolver. Organizations should upgrade to this version or later as soon as possible.

For detailed patch information, refer to the GitLab Patch Release Announcement. Additional technical details can be found in GitLab Work Item #586474 and the HackerOne Report #3483687.

Workarounds

• Restrict network access to the GitLab GraphQL endpoint using firewall rules or reverse proxy configurations
• Implement authentication requirements for GraphQL API access if operationally feasible
• Deploy a WAF with GraphQL-specific protections to limit query depth and complexity
• Consider temporarily disabling the GraphQL API if not critical to operations until patching is complete

# Example: Restrict GraphQL endpoint access via nginx configuration
location /api/graphql {
    # Allow only internal networks
    allow 10.0.0.0/8;
    allow 192.168.0.0/16;
    deny all;
    
    # Rate limiting
    limit_req zone=graphql_limit burst=10 nodelay;
    
    proxy_pass http://gitlab-workhorse;
}