CVE-2026-40471

CVE-2026-40471

hackage-server lacked Cross-Site Request Forgery (CSRF) protection across its endpoints. Scripts on foreign sites could trigger requests to hackage server, possibly abusing latent credentials to upload packages or perform other administrative actions. Some unauthenticated actions could also be abused (e.g. creating new user accounts).

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.002 (7.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-40471: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40471?
CVE-2026-40471 is a critical-severity vulnerability, classified under Cross-Site Request Forgery (CSRF). CVSS score: 9.6/10. Published 2026-04-23.
How severe is CVE-2026-40471?
Critical severity. CVSS v3 base score is 9.6 out of 10.