SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

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).

HIGH 8.4EPSS 0.38%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0
8.4 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.38% probability · 31th percentile
CISA KEV
Not listed
Weakness
CWE-611
Affected
w3/css validator
Source
cve-coordination@google.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.