High severity · published Feb 25, 2026
CVE-2026-1388
Inefficient Regular Expression Complexity in GitLab
7.5
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GI
GitLab · GitLab
9.2 before 18.7.5; 18.8 before 18.8.5; 18.9 before 18.9.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-1388
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-1388
Release Notes
https://about.gitlab.com/releases/2026/02/25/patch-release-gitlab-18-9-1-released/
Broken Link
https://gitlab.com/gitlab-org/gitlab/-/issues/587560
Permissions Required
https://hackerone.com/reports/3482893
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