CVE-2026-7427: GitLab CE/EE DoS Vulnerability

CVE-2026-7427 Overview

GitLab has patched a denial of service vulnerability affecting GitLab Community Edition (CE) and Enterprise Edition (EE). The flaw stems from improper input validation and allows an unauthenticated remote attacker to disrupt service availability under specific conditions. The issue is tracked as [CWE-770] (Allocation of Resources Without Limits or Throttling) and impacts GitLab versions from 18.5 through the fixed releases 19.0.6, 19.1.4, and 19.2.2. Because exploitation requires no authentication and can be triggered over the network, exposed GitLab instances are at direct risk of service disruption.

Critical Impact
Unauthenticated remote attackers can trigger a denial of service against vulnerable GitLab CE/EE instances, disrupting source control, CI/CD pipelines, and developer workflows.

Affected Products

GitLab CE/EE versions 18.5 up to (but not including) 19.0.6
GitLab CE/EE versions 19.1 up to (but not including) 19.1.4
GitLab CE/EE versions 19.2 up to (but not including) 19.2.2

Discovery Timeline

2026-08-12 - CVE-2026-7427 published to the National Vulnerability Database (NVD)
2026-08-12 - Last updated in NVD database
Vulnerability reported via HackerOne Security Report #3638799
GitLab remediation tracked in GitLab Work Item 598561

Technical Details for CVE-2026-7427

Vulnerability Analysis

The vulnerability resides in GitLab CE/EE input handling logic. GitLab fails to properly validate specific input under certain conditions, permitting an unauthenticated request to consume resources in an unbounded manner. This behavior maps to [CWE-770], where the application allocates resources without enforcing limits or throttling. The result is a denial of service that impacts availability but does not compromise confidentiality or integrity.

GitLab is a core DevOps platform hosting source code, issue tracking, and CI/CD workflows. A successful denial of service against a GitLab instance stalls build pipelines, blocks merges, and interrupts developer productivity. Public-facing GitLab servers face the greatest exposure because attackers do not need credentials or user interaction to trigger the condition.

Root Cause

The root cause is improper input validation in a network-accessible GitLab endpoint. Malformed or malicious input reaches processing logic that lacks bounds enforcement, driving resource exhaustion. GitLab has not published the specific component or endpoint publicly beyond the tracked work item and patch notes.

Attack Vector

An attacker sends a crafted request over the network to a vulnerable GitLab instance. No authentication, privileges, or user interaction are required. Repeated or sustained exploitation degrades or halts service for legitimate users. Refer to the GitLab Patch Release Note for 19.2.2 for vendor-published technical context.

Detection Methods for CVE-2026-7427

Indicators of Compromise

Unexplained spikes in CPU, memory, or worker process utilization on GitLab application servers
Elevated rates of failed or timed-out HTTP requests in gitlab-rails/production.log and gitlab-workhorse logs
Puma or Sidekiq workers repeatedly restarting or becoming unresponsive
Unauthenticated requests to GitLab endpoints originating from a small number of external IPs

Detection Strategies

Baseline normal request volumes and alert on anomalous surges from unauthenticated sources
Monitor GitLab health-check endpoints (/-/health, /-/readiness, /-/liveness) for degraded responses
Correlate reverse-proxy access logs (NGINX, HAProxy) with backend GitLab error rates to identify resource-exhaustion patterns
Track GitLab version banners across the estate to prioritize hosts still running vulnerable releases

Monitoring Recommendations

Forward GitLab application, Workhorse, and web server logs to a centralized SIEM for correlation and alerting
Enable rate-based alerts on 5xx responses and request-latency thresholds on GitLab reverse proxies
Monitor host-level metrics (CPU, memory, file descriptors) on GitLab nodes and alert on sustained saturation

How to Mitigate CVE-2026-7427

Immediate Actions Required

Upgrade GitLab CE/EE to version 19.2.2, 19.1.4, or 19.0.6 depending on your current release branch
Inventory all internal and internet-facing GitLab instances and confirm patched versions post-upgrade
Restrict network exposure of GitLab administrative and API endpoints to trusted networks where feasible
Review reverse-proxy logs for pre-patch exploitation attempts and unusual unauthenticated traffic

Patch Information

GitLab published patched releases 19.2.2, 19.1.4, and 19.0.6 that address the improper input validation. Administrators should apply the corresponding upgrade for their release branch. Full details are available in the GitLab Patch Release Note and the GitLab Work Item Update.

Workarounds

Place GitLab behind a reverse proxy or Web Application Firewall (WAF) with rate limiting on unauthenticated endpoints
Enforce IP allow-listing for GitLab access where the deployment model permits
Configure gitlab.rb throttling settings (gitlab_rails['rate_limit_requests_per_period']) to constrain unauthenticated request bursts until patches are applied

bash

# Example: enable unauthenticated request throttling in /etc/gitlab/gitlab.rb
gitlab_rails['rate_limit_requests_per_period'] = 300
gitlab_rails['rate_limit_period'] = 60

# Apply configuration changes
sudo gitlab-ctl reconfigure