Vulnerability in Kazeburo Plack\

CVE-2025-40926

Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely. The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will com…

EPSS: 0.004 (34.6th 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

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-40926?
CVE-2025-40926 is a critical-severity vulnerability in Kazeburo Plack\, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 9.8/10. Published 2026-03-05.
How severe is CVE-2025-40926?
Critical severity. CVSS v3 base score is 9.8 out of 10.