XSS in GitLab

CVE-2025-4278

An issue has been discovered in GitLab CE/EE affecting all versions starting with 18.0 before 18.0.2. Under certain conditions html injection in new search page could lead to account takeover.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.106 (95.7th percentile), scored .

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 96th percentile — 95.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-4278: rose from 0.090 to 0.106.

EPSS over last 30 days · oldest: 0.090 · newest: 0.106 · change: +0.017

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-4278?
CVE-2025-4278 is a high-severity vulnerability in GitLab, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 8.7/10. Published 2025-06-12.
How severe is CVE-2025-4278?
High severity. CVSS v3 base score is 8.7 out of 10.
Is CVE-2025-4278 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.