CVE-2026-1388

Name: CVE-2026-1388
Creator: NVD / NIST
Published: 2026-02-25T21:16:36.5+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.36%

Last modified Jun 17, 2026

CVE-2026-1388 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. GitLab has remediated an issue in GitLab CE/EE affecting all versions from 9.2 before 18.7.5, 18.8 before 18.8.5, and 18.9 before 18.9.1 that could have allowed an unauthenticated user to cause regular expression denial of service by sending specially crafted input to a merge request endpoint under certain conditions.. EPSS estimates a 0.36% chance of exploitation in the next 30 days.

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 9.2 before 18.7.5, 18.8 before 18.8.5, and 18.9 before 18.9.1 that could have allowed an unauthenticated user to cause regular expression denial of service by sending specially crafted input to a merge request endpoint under certain conditions.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.36%

27.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-1333

Affected Software

Vendor	Product	Versions
Gitlab	Gitlab	>= 9.2.0, < 18.7.5
Gitlab	Gitlab	>= 18.8.0, < 18.8.5
Gitlab	Gitlab	18.9.0

References

https://about.gitlab.com/releases/2026/02/25/patch-release-gitlab-18-9-1-released/Release Notes, Vendor Advisory
https://gitlab.com/gitlab-org/gitlab/-/issues/587560Broken Link
https://hackerone.com/reports/3482893Permissions Required

Timeline

Published: Feb 25, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-1388?

How severe is CVE-2026-1388?

CVE-2026-1388 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.

How do I fix CVE-2026-1388?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-1388?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST