LiveActive security incident?Get immediate response
CVE Record

CVE-2023-6736: Inefficient Regular Expression Complexity in GitLab

An issue has been discovered in GitLab EE affecting all versions starting from 11.3 before 16.7.6, all versions starting from 16.8 before 16.8.3, all versions starting from 16.9 before 16.9.1. It was possible for an attacker to cause a client-side denial of service using malicious crafted content in the CODEOWNERS file.

MediumCVSS 6.5Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a medium-severity GitLab EE issue where a malicious CODEOWNERS file could make a user's browser or GitLab client experience hang or become unavailable. It affects availability, not data theft or integrity, based on the supplied CVE data.

Executive priority

Treat this as a scheduled but meaningful availability fix. It is not described as data compromise, but it could disrupt developer workflows on affected GitLab EE instances, especially where repository write access is broadly delegated.

Technical view

GitLab EE versions from 11.3 before 16.7.6, 16.8 before 16.8.3, and 16.9 before 16.9.1 are affected by inefficient regular expression complexity in CODEOWNERS handling. A low-privileged attacker could cause client-side denial of service with crafted CODEOWNERS content.

Likely exposure

Exposure is most relevant to GitLab EE environments where users with low privileges can introduce or modify CODEOWNERS content in repositories viewed by others. The source bundle does not identify GitLab CE, GitLab.com-specific exposure, or other products as affected.

Exploitation context

The CVE records low attack complexity, network attack vector, low privileges required, and no user interaction. KEV is false, and the supplied sources do not establish active exploitation in the wild.

Researcher notes

The public bundle names CWE-1333 and describes crafted CODEOWNERS content causing client-side DoS. The linked GitLab and HackerOne references may require permissions, so analysis should remain anchored to the CVE record unless vendor-accessible details are available.

Mitigation direction

  • Upgrade GitLab EE to 16.7.6, 16.8.3, 16.9.1, or later supported versions.
  • Prioritize instances where untrusted users can modify repository CODEOWNERS files.
  • Limit CODEOWNERS editing to trusted maintainers until patched.
  • Check GitLab guidance if immediate upgrade is not possible.

Validation and detection

  • Inventory GitLab EE versions across self-managed environments.
  • Confirm no instance is in the affected version ranges.
  • Identify repositories where low-privileged users can change CODEOWNERS files.
  • Verify patched versions are deployed after remediation.
  • Review availability incidents tied to CODEOWNERS rendering or repository browsing.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-1333: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2023-6736 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2023-6736Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
GitLabGitLab11.3, 16.8, 16.9unaffected
Weakness

CWE details

CWE-1333

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-1333 · source CWE mapping

Inefficient Regular Expression Complexity

Inefficient Regular Expression Complexity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs