JavaScript Injection Vulnerability in GitLab Products
CVE-2026-1090

8.7HIGH

Key Information:

Vendor

Gitlab
Status
Gitlab
Vendor
CVE Published:
11 March 2026

What is CVE-2026-1090?

GitLab has identified a vulnerability in its CE and EE products that could enable an authenticated user to execute JavaScript in a web browser. This issue arises from insufficient sanitization of placeholder content during markdown processing when the 'markdown_placeholders' feature flag is activated. The vulnerability affects several versions of GitLab, necessitating prompt attention from users to ensure security.

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Deploy the Patch

Affected Version(s)

GitLab 10.6 < 18.7.6

GitLab 18.8 < 18.8.6

GitLab 18.9 < 18.9.2

References

https://hackerone.com/reports/3502450
technical-descriptionexploitpermissions-required
https://gitlab.com/gitlab-org/gitlab/-/work_items/586478
https://about.gitlab.com/releases/2026/03/11/patch-releas...

CVSS V3.1

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Thanks [yvvdwf](https://hackerone.com/yvvdwf) for reporting this vulnerability through our HackerOne bug bounty program
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