{"cve":"CVE-2025-40923","nvd":{"published":"2025-07-16T13:15:23.997","modified":"2026-06-17T09:22:17.947","status":"Deferred","description":"Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely.\n\nThe 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 small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.\n\nPredicable session ids could allow an attacker to gain access to systems.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","score":7.3},"cwes":["CWE-338","CWE-340"],"references":["https://github.com/plack/Plack-Middleware-Session/commit/1fbfbb355e34e7f4b3906f66cf958cedadd2b9be.patch","https://github.com/plack/Plack-Middleware-Session/pull/52","https://metacpan.org/release/MIYAGAWA/Plack-Middleware-Session-0.34/source/lib/Plack/Session/State.pm#L22","https://security.metacpan.org/docs/guides/random-data-for-security.html","http://www.openwall.com/lists/oss-security/2025/07/16/4"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:05:46.678065081+00:00"},"epss":{"cve":"CVE-2025-40923","score":0.0039,"percentile":0.33157,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}