CVE-2021-39941Public exploitNetwork attack vector

Default branch disclosure via project-page metadata

Published Dec 13, 2021 · Updated Aug 4, 2024

Information disclosure in GitLab CE/EE allows remote attackers to read default branch names of projects with member-only repositories. The project details view renders the restricted branch name in page metadata, including repository_ref and autocomplete attributes, despite denying repository access. Exploitation requires a visible project with repository access limited to members; the disclosed information is only the default branch name.

CVSS severity3.7
Low
EPSS probability1.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in GitLab CE/EE allows remote attackers to read default branch names of projects with member-only repositories. The project details view renders the restricted branch name in page metadata, including repository_ref and autocomplete attributes, despite denying repository access. Exploitation requires a visible project with repository access limited to members; the disclosed information is only the default branch name.

The record

CVE
CVE-2021-39941
Published
Dec 13, 2021
Updated
Aug 4, 2024
Vendor
GitLab
Product
GitLab
Classifications
CWE-200
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=>=12.0, <14.3.6
  2. Affected versionversion=>=14.4, <14.4.4
  3. Affected versionversion=>=14.5, <14.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GitLab · GitLabversion=>=12.0, <14.3.6; version=>=14.4, <14.4.4; version=>=14.5, <14.5.2

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
3.7GitLab Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor

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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