CVE-2026-6335 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in GitLab

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.11 before 18.11.3 that under certain conditions could have allowed an authenticated user to execute arbitrary code in another user's browser session due to improper sanitization.

Published: 2026-05-14 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-6335 is rated Low Risk (24.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.19%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-6335

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.02% 0.19% +0.17%
2 2026-05-14 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-6335

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.3 2.7 [email protected]

Weakness enumeration for CVE-2026-6335

GitHub Security Advisory for CVE-2026-6335

GHSA-3jrg-257v-4fw6 · Severity: medium — GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.11 before 18.11.3...

OS Trackers for CVE-2026-6335

vendor priority summary link
debian unimportant CVE-2026-6335 unimportant priority: Debian including 1 source packages (gitlab), 1 status rows across 1 suites (sid): resolved 1. https://security-tracker.debian.org/tracker/CVE-2026-6335
ubuntu medium CVE-2026-6335 medium priority: Ubuntu including 1 source packages (gitlab), 5 status rows across 5 suites (jammy, noble, questing, resolute, upstream): DNE 4, not-affected 1. https://ubuntu.com/security/CVE-2026-6335

Affected software / configurations for CVE-2026-6335

Vendor Product Version Raw CPE
gitlab gitlab >= 18.11.0, < 18.11.3 cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
gitlab gitlab >= 18.11.0, < 18.11.3 cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*

References for CVE-2026-6335

cvelogic Threat Intelligence