Vulnerability · Published Apr 23, 2026 · Assigned by redhat-cnalr
CVE-2026-40472Hackage package metadata stored XSS vulnerability
Critical 9.9
In plain English
A critical-severity cross-site scripting in hackage-server. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities).
Severity (CVSS 3.1)9.9Critical
Exploit odds (30 days)0.3%top 76.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| hackage-server | 0.1 – before * |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L