CVE-2025-8405 - CVE House
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Status published High CVE-2025-8405

Improper Encoding or Escaping of Output in GitLab

Vulnerability Description

GitLab has remediated a security issue in GitLab CE/EE affecting all versions from 17.1 before 18.4.6, 18.5 before 18.5.4, and 18.6 before 18.6.2 that could have allowed an authenticated user to perform unauthorized actions on behalf of other users by injecting malicious HTML into vulnerability code flow displays.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

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

References

More from GitLab

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CVE-2025-9958
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CVE-2025-9825
Missing Authorization in GitLab
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CVE-2025-9642
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in GitLab
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CVE-2025-9484
Missing Authorization in GitLab
Medium 4.3

Affected Vendor

Affected Software

GitLab
Vulnerable Versions:
17.1, 18.5, 18.6

Timeline

Official Publish: December 11th, 2025
Last Modified: February 26th, 2026
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

Weaknesses (CWE)

CWE-116

MITRE ATT&CK TTPs

T1189 Drive-by Compromise
Initial Access
T1190 Exploit Public-Facing Application
Initial Access
T1059 Command and Scripting Interpreter
Execution
T1565.002 Stored Data Manipulation
Impact