CVE-2026-40472CWE-79

Hackage package metadata stored XSS vulnerability

Critical · published April 23, 2026

CVSS v3.1
9.9
EPSS
0%
Percentile
35.9
In the wild
Unconfirmed
What it is

In hackage-server, user-controlled metadata from .cabal files are rendered into HTML

href attributes without proper sanitization, enabling stored

Cross-Site Scripting (XSS) attacks.

The record
Technical detail
CVSS v3.1
9.9 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
CVSS v4.0
Not supplied
EPSS
0.00427 · 35.9th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-04-23T15:00Z
EPSS history
Timeline
  • 23 APR 15:00Z
    Hackage package metadata stored XSS vulnerability
    cvelistv5