XXE in W3 CSS Validator
CVE-2025-1781
There is a XXE in W3CSS Validator versions before cssval-20250226 that allows an attacker to use specially-crafted XML objects to coerce server-side request forgery (SSRF). This could be exploited to read arbitrary local files if an attacker has access to exception messages.
Vulnerability class: XXE (XML External Entity)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (30.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- W3 CSS Validator
- W3c CSS Validator — versions < cssval-20250226
Weakness classification (CWE)
References
- github.com/google/security-research/security/advisories/GHSA-745m-xmq6-g6x7 (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-1781?
- CVE-2025-1781 is a medium-severity vulnerability in W3 CSS Validator, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 6.5/10. Published 2025-03-28.
- How severe is CVE-2025-1781?
- Medium severity. CVSS v3 base score is 6.5 out of 10.