CVE-2023-5356Public exploitNetwork attack vector

User impersonation via uncorrelated integration identities

Published Jan 12, 2024 · Updated Apr 28, 2026

Incorrect authorization in affected GitLab CE/EE versions allows remote authenticated users to execute slash commands as another user. The integration endpoint validates its token separately from attacker-supplied team and user identifiers without correlating those identities. Exploitation requires a configured Slack or Mattermost slash-command integration, high GitLab privileges, victim interaction, and known workspace identifiers; commands run with the victim's project permissions.

CVSS severity7.3
High
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in affected GitLab CE/EE versions allows remote authenticated users to execute slash commands as another user. The integration endpoint validates its token separately from attacker-supplied team and user identifiers without correlating those identities. Exploitation requires a configured Slack or Mattermost slash-command integration, high GitLab privileges, victim interaction, and known workspace identifiers; commands run with the victim's project permissions.

The record

CVE
CVE-2023-5356
Published
Jan 12, 2024
Updated
Apr 28, 2026
Vendor
GitLab
Product
GitLab
Classifications
CWE-863, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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=16.6 <16.6.4
  2. Affected versionversion=16.7 <16.7.2
  3. Affected versionversion=8.13 <16.5.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=16.6 <16.6.4; version=16.7 <16.7.2; version=8.13 <16.5.6

Published CVSS scores

7.3GitLabCVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/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

CWE-863Incorrect Authorization
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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