What is CVE-2026-87719?

CVE-2026-87719 is a critical-severity vulnerability in GitLab, classified under Deserialization of Untrusted Data. CVSS score: 9.9/10. Published 2026-09-12.

How severe is CVE-2026-87719?

Critical severity. CVSS v3 base score is 9.9 out of 10.

Deserialization in GitLab

CVE-2026-87719

GitLab has remediated an issue in GitLab EE affecting all versions from 18.3 before 19.1.8, 19.2 before 19.2.6, and 19.3 before 19.3.2 that under certain conditions could allow an authenticated user with Duo Chat access to obtain Advanced Search instance configurations and sensitive credentials using a specially crafted GraphQL subscription argument to bypass serialization and perform server object lookup.

Vulnerability class: Insecure Deserialization

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

Affected products

Gitlab

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

cve@gitlab.com
cve@gitlab.com (technical-description, permissions-required, exploit)

Frequently asked questions

What is CVE-2026-87719?: CVE-2026-87719 is a critical-severity vulnerability in GitLab, classified under Deserialization of Untrusted Data. CVSS score: 9.9/10. Published 2026-09-12.
How severe is CVE-2026-87719?: Critical severity. CVSS v3 base score is 9.9 out of 10.