What is CVE-2026-40472?

CVE-2026-40472 is a critical-severity vulnerability, classified under Cross-site Scripting. CVSS score: 9.9/10. Published 2026-04-23.

How severe is CVE-2026-40472?

Critical severity. CVSS v3 base score is 9.9 out of 10.

CVE-2026-40472

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.001 (18.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L.

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

osv.dev/vulnerability/HSEC-2026-0004

Frequently asked questions

What is CVE-2026-40472?: CVE-2026-40472 is a critical-severity vulnerability, classified under Cross-site Scripting. CVSS score: 9.9/10. Published 2026-04-23.
How severe is CVE-2026-40472?: Critical severity. CVSS v3 base score is 9.9 out of 10.