GitLab 18.10 < 18.10.4 / 18.11 < 18.11.1 (CVE-2026-5816)

high Nessus Plugin ID 309671

Synopsis

The version of GitLab installed on the remote host is affected by a vulnerability.

Description

The version of GitLab installed on the remote host is affected by a vulnerability, as follows:

- GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.10 before 18.10.4 and 18.11 before 18.11.1 that could have allowed an unauthenticated user to execute arbitrary JavaScript in a user's browser session due to improper path validation under certain conditions. (CVE-2026-5816)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to GitLab version 18.10.4, 18.11.1 or later.

See Also

http://www.nessus.org/u?9ca5b328

https://hackerone.com/reports/3572231

https://gitlab.com/gitlab-org/gitlab/-/work_items/592816

http://www.nessus.org/u?3863423b

Plugin Details

Severity: High

ID: 309671

File Name: gitlab_cve-2026-5816.nasl

Version: 1.2

Type: Combined

Agent: unix

Family: CGI abuses

Published: 4/22/2026

Updated: 4/24/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.0

CVSS v2

Risk Factor: High

Base Score: 7.1

Temporal Score: 5.3

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

CVSS Score Source: CVE-2026-5816

CVSS v3

Risk Factor: High

Base Score: 8

Temporal Score: 7

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:gitlab:gitlab

Required KB Items: installed_sw/GitLab

Exploit Ease: No known exploits are available

Patch Publication Date: 4/22/2026

Vulnerability Publication Date: 4/22/2026

Reference Information

CVE: CVE-2026-5816

IAVA: 2026-A-0392