CVE-2023-6688: Inefficient Regular Expression Complexity in GitLab

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-14 · updated 2026-06-17
Weakness: CWE-1333

Description

An issue has been discovered in GitLab CE/EE affecting all versions starting from 16.11 prior to 16.11.2. A problem with the processing logic for Google Chat Messages integration may lead to a regular expression DoS attack on the server.

Affected products

GitLab: from 16.11.0 before 16.11.2 — fixed in 16.11.2

How to fix

Upgrade to a fixed version: GitLab 16.11.2. Check the vendor advisory for mitigations.

References

https://gitlab.com/gitlab-org/gitlab/-/issues/434854
https://hackerone.com/reports/2270362
https://gitlab.com/gitlab-org/gitlab/-/issues/434854
https://hackerone.com/reports/2270362

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