CVE-2023-3424: Inefficient Regular Expression Complexity in GitLab

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-07-13 · updated 2026-06-17
Weakness: CWE-1333

Description

An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.3 before 15.11.10, all versions starting from 16.0 before 16.0.6, all versions starting from 16.1 before 16.1.1. A Regular Expression Denial of Service was possible via sending crafted payloads to the preview_markdown endpoint.

Affected products

GitLab: from 10.3.0 before 15.11.10; from 16.0.0 before 16.0.6; from 16.1.0 before 16.1.1 — fixed in 15.11.10, 16.0.6, 16.1.1

How to fix

Upgrade to a fixed version: GitLab 15.11.10, 16.0.6, 16.1.1. Check the vendor advisory for mitigations.

References

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