CVE-2026-87719

Think of GitLab as your business’s secure filing cabinet. This vulnerability is like a hidden trick in one specific feature (Duo Chat + GraphQL) that can let an approved insider—if they have access to Duo Chat—pull out other sensitive “internal papers,” including secrets and system configuration.

Even though it requires a logged-in user with Duo Chat access, the results can be serious because exposed credentials can be used to access other parts of your environment.

This matters if you run GitLab (GitLab EE) and your installed version is within one of the vulnerable ranges, because a specifically crafted GraphQL request can expose internal settings and sensitive credentials.

It’s most relevant when an attacker has (or already controls) a user account with Duo Chat access—because no special clicks or user interaction are needed beyond that authenticated access.

The risk is real for any vulnerable GitLab EE installation where Duo Chat-capable accounts exist (including situations where accounts may be compromised), since the attack is network-based and reaches the server through the GitLab feature.

This is RED because exploitation attempts were reported in the wild soon after disclosure, and the issue can lead to exposure of sensitive credentials and internal configuration.

Since it’s triggered by an authenticated user with Duo Chat access and requires no user interaction, an attacker who has gained such access can target the server quickly.

1. Confirm exposure (version check)

   • Identify your exact GitLab EE version.
   • Determine whether it falls into any vulnerable range:
     • 18.3 < v < 19.1.8
     • 19.2 < v < 19.2.6
     • 19.3 < v < 19.3.2

2. Upgrade to the fixed version (remediation)

   • Upgrade GitLab EE to one of the following fixed versions or later:
     • 19.1.8 and above
     • 19.2.6 and above
     • 19.3.2 and above

3. Validate after upgrade

   • Verify the GitLab version now shows as fixed (one of the above ranges no longer applies).
   • Confirm the Duo Chat/GraphQL-related components are operating normally.

4. Temporary containment if you cannot upgrade immediately

   • If feasible in your environment, restrict or limit Duo Chat access to only the minimum required users/accounts until you can patch.
   • If there are indications of compromise or suspicious activity, treat this as a credential exposure scenario and rotate any exposed secrets you suspect may be impacted.
   • Review access controls and ensure no unexpected users have Duo Chat access.

5. What to monitor

   • Monitor GitLab logs for unusual GraphQL subscription activity and unexpected access patterns by Duo Chat-capable accounts, especially around the time you received the vulnerability disclosure.

CISA KEV note: this CVE was not listed in the CISA KEV set based on the provided findings.

Severity is high (reported as critical with a very high impact profile: confidentiality, integrity, and availability are all indicated as affected).

Mechanism: The issue is a deserialization of untrusted data problem (CWE-502) in GitLab EE that can be triggered by an authenticated user with Duo Chat access. The user can send a specially crafted GraphQL subscription argument that bypasses safety checks and enables server-side object lookup, resulting in exposure of Advanced Search instance configurations and sensitive credentials.

Exploitation status: In-the-wild exploitation attempts/probing were reported shortly after disclosure (first reported 2026-09-11). No public exploit code is on record.

KEV: Not listed in CISA KEV in the provided findings.

Fix: GitLab remediation is available via upgrades to 19.1.8, 19.2.6, and 19.3.2 (fixed versions stated in the findings).