CVE-2023-6840Public exploitNetwork attack vector

Policy bypass via unchecked protected-branch rename

Published Feb 7, 2024 · Updated Apr 24, 2026

Missing authorization in affected GitLab EE 16.x releases allows remote authenticated Maintainers to bypass protected-branch policy. ProtectedBranches::UpdateService accepts a protected-branch name change without enforcing block_branch_modification, moving the branch outside the policy match. Maintainer access and an enabled merge request approval policy are required; the bypass can permit unreviewed code changes.

CVSS severity6.7
Medium
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in affected GitLab EE 16.x releases allows remote authenticated Maintainers to bypass protected-branch policy. ProtectedBranches::UpdateService accepts a protected-branch name change without enforcing block_branch_modification, moving the branch outside the policy match. Maintainer access and an enabled merge request approval policy are required; the bypass can permit unreviewed code changes.

The record

CVE
CVE-2023-6840
Published
Feb 7, 2024
Updated
Apr 24, 2026
Vendor
GitLab
Product
GitLab
Classifications
CWE-862, T1562.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 7, 2024CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.4 <16.6.7
  2. Affected versionversion=16.7 <16.7.5
  3. Affected versionversion=16.8 <16.8.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=16.4 <16.6.7; version=16.7 <16.7.5; version=16.8 <16.8.2

Published CVSS scores

6.7GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1562.001Impair Defenses: Disable or Modify Tools

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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