CVE-2023-4008Public exploitNetwork attack vector

Hosted-site traffic hijacking via namespace collision

Published Aug 3, 2023 · Updated Jun 2, 2026

Incorrect ownership assignment in GitLab CE/EE allows remote authenticated users to hijack traffic for Pages sites through unique URLs. The unique-domain builder separates namespace, project, and random-suffix values with hyphens, allowing a user-created namespace containing a known suffix to collide and take URL-lookup priority. Exploitation requires knowledge of the random suffix and project creation rights; successful takeover serves attacker-controlled content for the victim's Pages URL.

CVSS severity5.3
Medium
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect ownership assignment in GitLab CE/EE allows remote authenticated users to hijack traffic for Pages sites through unique URLs. The unique-domain builder separates namespace, project, and random-suffix values with hyphens, allowing a user-created namespace containing a known suffix to collide and take URL-lookup priority. Exploitation requires knowledge of the random suffix and project creation rights; successful takeover serves attacker-controlled content for the victim's Pages URL.

The record

CVE
CVE-2023-4008
Published
Aug 3, 2023
Updated
Jun 2, 2026
Vendor
GitLab
Product
GitLab
Classifications
CWE-708, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 2, 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=15.9 <16.0.8
  2. Affected versionversion=16.1 <16.1.3
  3. Affected versionversion=16.2 <16.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=15.9 <16.0.8; version=16.1 <16.1.3; version=16.2 <16.2.2

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.3GitLab Inc.CVSS: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 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-708Incorrect Ownership Assignment
T1190Exploit Public-Facing Application

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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