Redirect Vulnerability in GitLab AI Gateway Affects Multiple Versions
CVE-2026-75871

8.2HIGH

Key Information:

Vendor

Gitlab
Status
Gitlab Ai Gateway
Vendor
CVE Published:
27 August 2026

What is CVE-2026-75871?

A vulnerability in the GitLab AI Gateway component has been identified, affecting specific versions between 18.10 and 19.2.2. This issue could permit an authenticated user with Duo Agent Platform access to redirect outbound model requests to an untrusted external endpoint. By deliberately crafting the inline flow configuration to override the HTTP Host header, sensitive credentials related to Google Cloud Vertex services, including private signing keys, may be exposed. Mitigation steps have been provided by GitLab to address the identified risk.

Affected Version(s)

GitLab AI Gateway 18.10 < 19.0.12

GitLab AI Gateway 19.1 < 19.1.7

GitLab AI Gateway 19.2 < 19.2.2

References

https://gitlab.com/gitlab-org/gitlab/-/work_items/616990
https://hackerone.com/reports/3945100
technical-descriptionexploitpermissions-required

CVSS V3.1

Score:
8.2
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
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
.