Review reviewHigh

CVE-2026-5173

GitLab GitLab, gitlab

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 16.9.6 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3 that could have allowed an authenticated user to invoke unintended server-side methods through websocket connections due to improper access control.

CVSS
8.5
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.04.09
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 8.5

Vulnerability overview

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 16.9.6 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3 that could have allowed an authenticated user to invoke unintended server-side methods through websocket connections due to improper access control.

Affected product and versions

Product
GitLab GitLab, gitlab
Affected versions
>= 16.9.6 < 18.8.9, >= 18.9 < 18.9.5, >= 18.10 < 18.10.3, >= 18.9.0 < 18.9.5, >= 18.10.0 < 18.10.3
Fixed versions
18.8.9, 18.9.5, 18.10.3

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that GitLab GitLab, gitlab and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
CWE
CWE-749