CVE-2026-1752: GitLab EE Auth Bypass Vulnerability

CVE-2026-1752 Overview

An improper authorization vulnerability has been identified in GitLab Enterprise Edition (EE) that affects all versions from 11.3 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3. This vulnerability allows an authenticated user with developer-role permissions to modify protected environment settings due to improper authorization checks in the API.

Critical Impact

Authenticated users with limited developer permissions can bypass authorization controls to modify protected environment configurations, potentially compromising deployment security and CI/CD pipeline integrity.

Affected Products

• GitLab EE versions 11.3 to before 18.8.9
• GitLab EE versions 18.9 to before 18.9.5
• GitLab EE versions 18.10 to before 18.10.3

Discovery Timeline

• 2026-04-08 - CVE-2026-1752 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2026-1752

Vulnerability Analysis

This vulnerability is classified as CWE-863 (Incorrect Authorization), indicating a flaw in how GitLab EE validates user permissions when processing API requests related to protected environment settings. The issue occurs because the API endpoint responsible for managing protected environments does not properly verify that the requesting user has the appropriate privilege level to perform modification operations.

In typical GitLab deployments, protected environments are used to safeguard critical deployment targets such as production or staging environments. These environments should only be modifiable by users with maintainer or owner-level permissions. However, this vulnerability allows users with only developer-role permissions to circumvent these restrictions.

The attack can be conducted remotely over the network and requires low attack complexity, but does require authentication with at least developer-level access. The impact is limited to integrity, with no direct effect on confidentiality or availability of data.

Root Cause

The root cause stems from insufficient authorization validation in the GitLab EE API layer. When processing requests to modify protected environment settings, the application fails to adequately verify that the authenticated user possesses the required permission level. The authorization logic incorrectly accepts developer-level permissions for operations that should require maintainer or higher privileges.

Attack Vector

An attacker with developer-level access to a GitLab EE instance can exploit this vulnerability through the API. The attack scenario involves:

1. Authenticating to the GitLab instance with valid developer credentials
2. Crafting API requests targeting protected environment configuration endpoints
3. Submitting modification requests that should be rejected based on the user's permission level
4. Successfully altering protected environment settings despite insufficient privileges

The vulnerability is exploited via network-based API calls. For detailed technical information, refer to the HackerOne Report #3533545 and GitLab Work Item #588413.

Detection Methods for CVE-2026-1752

Indicators of Compromise

• Unexpected modifications to protected environment configurations by users without maintainer privileges
• API audit logs showing protected environment changes from developer-level accounts
• Changes to deployment protection rules that were not authorized through normal approval workflows

Detection Strategies

• Review GitLab audit logs for API calls to protected environment endpoints from users with developer roles
• Monitor for changes to protected environment settings and cross-reference with user permission levels
• Implement alerts for any modifications to critical deployment environments outside of change windows

Monitoring Recommendations

• Enable comprehensive audit logging for all protected environment configuration changes
• Configure SIEM rules to correlate user permission levels with protected environment modification events
• Establish baseline behavior for protected environment changes and alert on deviations

How to Mitigate CVE-2026-1752

Immediate Actions Required

• Upgrade GitLab EE to version 18.8.9, 18.9.5, or 18.10.3 or later immediately
• Review protected environment configurations for any unauthorized changes
• Audit user access logs to identify potential exploitation attempts
• Temporarily restrict API access to protected environment endpoints if patching cannot be performed immediately

Patch Information

GitLab has released patches addressing this vulnerability in versions 18.8.9, 18.9.5, and 18.10.3. Organizations should prioritize upgrading to one of these patched versions based on their current deployment. For complete patch details, see the GitLab Patch Release Announcement.

Workarounds

• Implement network-level restrictions to limit API access to trusted sources only
• Conduct a review of all users with developer-level permissions and temporarily elevate scrutiny on their activities
• Consider temporarily disabling API-based management of protected environments if business operations permit
• Enable additional approval workflows for protected environment changes as a compensating control

# Verify current GitLab version
gitlab-rake gitlab:env:info

# Check for protected environment configuration changes in audit logs
gitlab-rails console -e production
# In console: AuditEvent.where(entity_type: 'ProtectedEnvironment').order(created_at: :desc).limit(50)