Authentication Bypass in GitLab EE Software by GitLab
CVE-2026-87719

9.9CRITICAL

Key Information:

Vendor

Gitlab
Status
Gitlab
Vendor
CVE Published:
12 September 2026

What is CVE-2026-87719?

A vulnerability in GitLab EE allows an authenticated user with access to Duo Chat to exploit flaws in GraphQL subscription arguments. Under specific conditions, this flaw permits the user to bypass serialization processes and perform unauthorized server object lookups. Consequently, this could lead to the exposure of Advanced Search instance configurations and sensitive credentials that should be protected.

Affected Version(s)

GitLab 18.3 < 19.1.8

GitLab 19.2 < 19.2.6

GitLab 19.3 < 19.3.2

References

https://gitlab.com/gitlab-org/gitlab/-/work_items/628160
https://hackerone.com/reports/4012289
technical-descriptionexploitpermissions-required

CVSS V3.1

Score:
9.9
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Thanks [kyyblin](https://hackerone.com/kyyblin) for reporting this vulnerability through our HackerOne bug bounty program
.