CVE-2021-39903Public exploitNetwork attack vector

Restricted visibility bypass via unchecked API updates

Published Nov 4, 2021 · Updated Aug 4, 2024

Improper authorization in GitLab 13.0 through 14.4.0 allows remote authenticated users to override restricted project or group visibility. The project and group update API routes accept a visibility value without enforcing the instance administrator's restricted-level setting. A project or group owner with an access token can reach the flaw, and selecting public visibility exposes repository content without login.

CVSS severity6.5
Medium
EPSS probability1.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in GitLab 13.0 through 14.4.0 allows remote authenticated users to override restricted project or group visibility. The project and group update API routes accept a visibility value without enforcing the instance administrator's restricted-level setting. A project or group owner with an access token can reach the flaw, and selecting public visibility exposes repository content without login.

The record

CVE
CVE-2021-39903
Published
Nov 4, 2021
Updated
Aug 4, 2024
Vendor
GitLab
Product
GitLab
Classifications
T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 4, 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=>=13.0, <14.2.6
  2. Affected versionversion=>=14.3, <14.3.4
  3. Affected versionversion=>=14.4, <14.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=>=13.0, <14.2.6; version=>=14.3, <14.3.4; version=>=14.4, <14.4.1

Published CVSS scores

6.5GitLabCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1565.001Stored Data Manipulation

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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