CVE-2025-8014: GitLab GraphQL DoS Vulnerability

CVE-2025-8014 Overview

A Denial of Service (DoS) vulnerability exists in the GraphQL endpoints of GitLab Enterprise Edition (EE) and Community Edition (CE). This vulnerability affects all versions from 11.10 and allows unauthenticated users to potentially bypass query complexity limits, leading to resource exhaustion and service disruption.

Critical Impact

Unauthenticated attackers can exploit this GraphQL vulnerability to exhaust server resources, causing service disruption and potentially rendering GitLab instances unavailable to legitimate users.

Affected Products

• GitLab Community Edition versions 11.10 prior to 18.2.7
• GitLab Community Edition versions 18.3 prior to 18.3.3
• GitLab Community Edition version 18.4.0 prior to 18.4.1
• GitLab Enterprise Edition versions 11.10 prior to 18.2.7
• GitLab Enterprise Edition versions 18.3 prior to 18.3.3
• GitLab Enterprise Edition version 18.4.0 prior to 18.4.1

Discovery Timeline

• 2025-09-27 - CVE-2025-8014 published to NVD
• 2025-10-03 - Last updated in NVD database

Technical Details for CVE-2025-8014

Vulnerability Analysis

This vulnerability is classified under CWE-770 (Allocation of Resources Without Limits or Throttling). The flaw resides in GitLab's GraphQL API implementation, which is a critical component used for querying and manipulating data across the GitLab platform.

GraphQL APIs are inherently susceptible to resource exhaustion attacks due to their flexible query structure, which allows clients to request deeply nested or complex data relationships in a single query. GitLab implements query complexity limits to prevent abuse; however, this vulnerability allows attackers to circumvent these protective mechanisms.

The issue can be exploited remotely over the network without requiring authentication. When successfully exploited, attackers can craft malicious GraphQL queries that bypass the complexity validation, causing excessive memory and CPU consumption on the target server.

Root Cause

The root cause of this vulnerability is improper allocation of resources without adequate limits or throttling (CWE-770). The GraphQL endpoint fails to properly enforce query complexity limits under certain conditions, allowing crafted queries to consume disproportionate server resources. This represents a failure in the resource management and input validation layers of the GraphQL query parser.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker can target any publicly accessible GitLab instance by sending specially crafted GraphQL queries to the /api/graphql endpoint. The queries are designed to exploit the complexity limit bypass, triggering recursive or deeply nested data fetching operations that consume excessive CPU, memory, or database resources.

Since no authentication is required, this vulnerability presents a significant risk to any GitLab deployment with exposed GraphQL endpoints. Attackers can repeatedly send malicious queries to maintain the denial of service condition.

Detection Methods for CVE-2025-8014

Indicators of Compromise

• Unusual spikes in GraphQL API request volume, particularly from single IP addresses or user agents
• Elevated server resource consumption (CPU, memory) correlated with GraphQL endpoint activity
• Slow or unresponsive GitLab services affecting repository operations, CI/CD pipelines, and user access
• Error logs indicating query complexity or timeout issues in the GraphQL service

Detection Strategies

• Monitor GraphQL endpoint (/api/graphql) for abnormal request patterns and high query complexity scores
• Implement rate limiting detection rules that flag excessive requests from unauthenticated sources
• Configure alerting for sudden increases in server resource utilization tied to API traffic
• Review web application firewall (WAF) logs for patterns indicative of GraphQL abuse attacks

Monitoring Recommendations

• Enable detailed logging for GraphQL query execution including complexity scores and execution times
• Set up real-time alerting for resource exhaustion conditions on GitLab application servers
• Monitor database connection pools and query execution times for anomalies
• Implement network traffic analysis to identify high-volume GraphQL request sources

How to Mitigate CVE-2025-8014

Immediate Actions Required

• Upgrade GitLab to patched versions: 18.2.7, 18.3.3, or 18.4.1 or later immediately
• Implement rate limiting on the GraphQL endpoint at the reverse proxy or WAF level
• Consider temporarily restricting access to the GraphQL API from untrusted networks if immediate patching is not feasible
• Review and harden existing query complexity configurations in GitLab settings

Patch Information

GitLab has released security patches addressing this vulnerability. Organizations should upgrade to the following minimum versions:

• GitLab CE/EE version 18.2.7 for the 18.2.x branch
• GitLab CE/EE version 18.3.3 for the 18.3.x branch
• GitLab CE/EE version 18.4.1 for the 18.4.x branch

For additional details, refer to the GitLab Issue Report #556838 and the HackerOne Report #3228134.

Workarounds

• Implement network-level rate limiting for the /api/graphql endpoint to throttle excessive requests
• Configure a Web Application Firewall (WAF) to block requests with unusually large or complex GraphQL query payloads
• Restrict access to the GraphQL API by requiring authentication or limiting to trusted IP ranges
• Monitor and alert on resource utilization to quickly identify and respond to active exploitation attempts

# Example: Rate limiting configuration for NGINX reverse proxy
# Add to server block or location configuration for GitLab

location /api/graphql {
    # Limit requests to 10 per second per IP with burst of 20
    limit_req zone=graphql_limit burst=20 nodelay;
    limit_req_status 429;
    
    # Optional: Restrict to authenticated users only
    # auth_request /auth;
    
    proxy_pass http://gitlab_upstream;
}

# Define the rate limit zone in http block
# limit_req_zone $binary_remote_addr zone=graphql_limit:10m rate=10r/s;