Vulnerability · Published Sep 12, 2026 · Assigned by GitLab

CVE-2026-87719Deserialization of Untrusted Data in GitLab

Critical 9.9

In plain English

A critical-severity unsafe deserialization in GitLab from GitLab. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities).

Severity (CVSS 3.1)9.9Critical
Exploit odds (30 days)0.6%top 52.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

VendorProductVersions
GitLab GitLab 18.3 – before 18.11.1219.0 – before 19.0.919.1 – before 19.1.819.2 – before 19.2.619.3 – before 19.3.2

Weakness: CWE-502 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References