What is CVE-2025-40923?

CVE-2025-40923 is a high-severity vulnerability in Miyagawa Plack::middleware::session, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 7.3/10. Published 2025-07-16.

How severe is CVE-2025-40923?

High severity. CVSS v3 base score is 7.3 out of 10.

Vulnerability in Miyagawa Plack::middleware::session

CVE-2025-40923

Plack-Middleware-Session before version 0.35 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 come from a sm…

EPSS: 0.003 (25.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

Affected products

Miyagawa Plack::middleware::session — versions 0.01

Weakness classification (CWE)

CWE-338 — Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CWE-340

References

9b29abf9-4ab0-4765-b253-1875cd9b441e
9b29abf9-4ab0-4765-b253-1875cd9b441e
9b29abf9-4ab0-4765-b253-1875cd9b441e (patch)
9b29abf9-4ab0-4765-b253-1875cd9b441e
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2025-40923?: CVE-2025-40923 is a high-severity vulnerability in Miyagawa Plack::middleware::session, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 7.3/10. Published 2025-07-16.
How severe is CVE-2025-40923?: High severity. CVSS v3 base score is 7.3 out of 10.