GitLab Community Edition/Enterprise Edition up to 18.8.8/18.9.4/18.10.2 Websocket Connection routine

CVSS Meta Temp Score
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CTI Interest Score
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7.2$0-$5k1.16

Summaryinfo

A vulnerability described as critical has been identified in GitLab Community Edition and Enterprise Edition up to 18.8.8/18.9.4/18.10.2. This vulnerability affects unknown code of the component Websocket Connection Handler. Such manipulation leads to routine. This vulnerability is referenced as CVE-2026-5173. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in GitLab Community Edition and Enterprise Edition up to 18.8.8/18.9.4/18.10.2. It has been rated as critical. Affected by this issue is an unknown code block of the component Websocket Connection Handler. The manipulation with an unknown input leads to a routine vulnerability. Using CWE to declare the problem leads to CWE-749. The product provides an Applications Programming Interface (API) or similar interface for interaction with external actors, but the interface includes a dangerous method or function that is not properly restricted. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at gitlab.com. This vulnerability is handled as CVE-2026-5173 since 03/30/2026. The exploitation is known to be easy. The attack may be launched remotely. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 305636 (GitLab 16.9.6 < 18.8.9 / 18.9 < 18.9.5 / 18.10 < 18.10.3 (CVE-2026-5173)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 18.8.9, 18.9.5 or 18.10.3 eliminates this vulnerability. The upgrade is hosted for download at about.gitlab.com.

The vulnerability is also documented in the databases at Tenable (305636) and EUVD (EUVD-2026-20802). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.4
VulDB Meta Temp Score: 7.2

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.5
CNA Vector (GitLab): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Routine
CWE: CWE-749
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 305636
Nessus Name: GitLab 16.9.6 < 18.8.9 / 18.9 < 18.9.5 / 18.10 < 18.10.3 (CVE-2026-5173)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Community Edition/Enterprise Edition 18.8.9/18.9.5/18.10.3

Timelineinfo

03/30/2026 CVE reserved
04/09/2026 +10 days Advisory disclosed
04/09/2026 +0 days VulDB entry created
04/09/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: gitlab.com

Advisory: gitlab.com
Status: Confirmed

CVE: CVE-2026-5173 (🔒)
GCVE (CVE): GCVE-0-2026-5173
GCVE (VulDB): GCVE-100-356480
EUVD: 🔒

Entryinfo

Created: 04/09/2026 02:47
Updated: 04/09/2026 09:44
Changes: 04/09/2026 02:47 (65), 04/09/2026 03:24 (1), 04/09/2026 09:44 (2)
Complete: 🔍
Cache ID: 216:0BB:103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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