CVE-2026-5173

HIGH

Exposed Dangerous Method or Function in GitLab

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-5173. PoCs published by 0xBlackash.

AI-analyzed exploit summary This repository contains a functional Python-based PoC for CVE-2026-5173, which exploits a WebSocket vulnerability in GitLab to execute unauthorized GraphQL queries. The exploit demonstrates unauthorized access to sensitive data via the GraphqlChannel.

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 16.9.6 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3 that could have allowed an authenticated user to invoke unintended server-side methods through websocket connections due to improper access control.

Exploits (1)

nomisec WORKING POC
by 0xBlackash · poc
https://github.com/0xBlackash/CVE-2026-5173

This repository contains a functional Python-based PoC for CVE-2026-5173, which exploits a WebSocket vulnerability in GitLab to execute unauthorized GraphQL queries. The exploit demonstrates unauthorized access to sensitive data via the GraphqlChannel.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: GitLab CE/EE (versions 16.9.6 to 18.10.2)
Auth required
Prerequisites: GitLab instance with WebSocket endpoint accessible · Optional Personal Access Token for authenticated testing
devstral-2 · analyzed Apr 09, 2026 Full analysis →

References (2)

Core 2

Scores

CVSS v3 8.5
EPSS 0.0040
EPSS Percentile 31.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-749
Status published
Products (4)
GitLab/GitLab 16.9.6 - 18.8.9
gitlab/gitlab 16.9.6 - 18.8.9 (2 CPE variants)
GitLab/GitLab 18.10 - 18.10.3
GitLab/GitLab 18.9 - 18.9.5
Published Apr 08, 2026
Tracked Since Apr 09, 2026