CVE-2026-1456

MEDIUM

GitLab 18.7-18.7.3 and 18.8-18.8.3 - Unauthenticated Denial of Service via Markdown Preview CPU Exhaustion

Title source: llm
STIX 2.1

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.7 before 18.7.4, and 18.8 before 18.8.4 that could have allowed an unauthenticated user to cause denial of service through CPU exhaustion by submitting specially crafted markdown files that trigger exponential processing in markdown preview.

References (3)

Core 3
Core References
Broken Link, Issue Tracking issue-tracking permissions-required
https://gitlab.com/gitlab-org/gitlab/-/issues/587688
Permissions Required technical-description exploit permissions-required
https://hackerone.com/reports/3517928

Scores

CVSS v3 6.5
EPSS 0.0036
EPSS Percentile 28.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-770
Status published
Products (1)
gitlab/gitlab 18.7.0 - 18.7.4 (2 CPE variants)
Published Feb 11, 2026
Tracked Since Feb 18, 2026