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.
References1
Metrics
- CVSS 3.1
-
9.9
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L - EPSS — exploit probability
- 0% percentile: 23 · as of 13 November 2026
- CWE
- CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.