CVE-2026-87719

Deserialization of Untrusted Data in GitLab

State: Published
Severity: 9.9 Critical
Published: Sep 12, 2026
Updated: Sep 23, 2026
Reserved: Sep 9, 2026

Description

GitLab has remediated an issue in GitLab EE affecting all versions from 18.3 before 18.11.12, 19.0 before 19.0.9, 19.1 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.

Scores

CVSS	Score	Vector	Source
3.1	9.9 Critical	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H	GitLab

Weaknesses

CWE-502 Deserialization of Untrusted Data

Affected Products

Product	Versions
GitLabGitLab	18.3 to before 18.11.12Affected 19.0 to before 19.0.9Affected 19.1 to before 19.1.8Affected 19.2 to before 19.2.6Affected 19.3 to before 19.3.2Affected

References

https://gitlab.com/gitlab-org/gitlab/-/work_items/628160
HackerOne Bug Bounty Report #4012289technical-descriptionexploitpermissions-required

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