VulnerabilityAwaiting Analysis

CVE-2026-40472

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.

CRITICAL 9.9EPSS 0.30%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 9.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
EPSS: 0.30% probability · 23th percentile
CISA KEV: Not listed
Weakness: CWE-79
Source: 74b3a70d-cca6-4d34-9789-e83b222ae3be

References

https://osv.dev/vulnerability/HSEC-2026-0004

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