CVE-2026-5173Public exploitNetwork attack vector

Authenticated server-side method invocation via ActionCable dispatch

Published Apr 8, 2026 · Updated Apr 8, 2026

Improper access control in affected GitLab CE/EE releases allows remote authenticated users to invoke server-side methods over WebSockets. ActionCable includes inherited public methods on ApplicationCable::Channel in its callable-action set, then public_send dispatches the supplied name with up to one deserialized JSON argument. Any authenticated account with a project WebSocket connection can reach these methods; published sources do not identify the specific data exposed or modified.

CVSS severity8.5
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in affected GitLab CE/EE releases allows remote authenticated users to invoke server-side methods over WebSockets. ActionCable includes inherited public methods on ApplicationCable::Channel in its callable-action set, then public_send dispatches the supplied name with up to one deserialized JSON argument. Any authenticated account with a project WebSocket connection can reach these methods; published sources do not identify the specific data exposed or modified.

The record

CVE
CVE-2026-5173
Published
Apr 8, 2026
Updated
Apr 8, 2026
Vendor
GitLab
Product
GitLab
Classifications
CWE-749, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record 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=16.9.6 <18.8.9
  2. Affected versionversion=18.10 <18.10.3
  3. Affected versionversion=18.9 <18.9.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=16.9.6 <18.8.9; version=18.10 <18.10.3; version=18.9 <18.9.5

Published CVSS scores

8.5GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/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-749Exposed Dangerous Method or Function
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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