What is CVE-2026-3256?

CVE-2026-3256 is a critical-severity vulnerability in Ktat Http\, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 9.8/10. Published 2026-03-28.

How severe is CVE-2026-3256?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Ktat Http\

CVE-2026-3256

HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids. HTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, the…

EPSS: 0.005 (41.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Ktat Http\ — versions \
Ktat Http::session — versions 0

Weakness classification (CWE)

References

9b29abf9-4ab0-4765-b253-1875cd9b441e (Product)
9b29abf9-4ab0-4765-b253-1875cd9b441e (Product)
9b29abf9-4ab0-4765-b253-1875cd9b441e (technical-description, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes)

Frequently asked questions

What is CVE-2026-3256?: CVE-2026-3256 is a critical-severity vulnerability in Ktat Http\, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 9.8/10. Published 2026-03-28.
How severe is CVE-2026-3256?: Critical severity. CVSS v3 base score is 9.8 out of 10.