{"id":"CVE-2025-40923","aliases":["DEBIAN-CVE-2025-40923","EUVD-2025-21693","GHSA-868p-jhqw-wrgr","UBUNTU-CVE-2025-40923"],"status":"published","title":"Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely","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.","severity":{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"high","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-09","score":0.0039,"percentile":0.33406,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-338","CWE-340"],"published":"2025-07-16T13:05:03Z","modified":"2026-10-28T02:30:43Z","fixes":[{"ecosystem":"Debian:14","package":"libplack-middleware-session-perl","fixed_in":["0.36-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.33-2","0.34-1","0.36-1"]},{"source":"osv","ecosystem":"Debian:13","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.34-1","0.36-1"]},{"source":"osv","ecosystem":"Debian:14","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.36-1"}]}],"versions":["0.34-1"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.30-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.30-1","0.30-2"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.32-1","0.33-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.33-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.33-2"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"libplack-middleware-session-perl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.34-1","0.36-1"]}],"products":[{"vendor":"miyagawa","product":"plack::middleware::session"}],"references":[{"url":"https://metacpan.org/release/MIYAGAWA/Plack-Middleware-Session-0.34/source/lib/Plack/Session/State.pm#L22","tags":["web","report"]},{"url":"https://github.com/plack/Plack-Middleware-Session/pull/52","tags":["fix","report"]},{"url":"https://github.com/plack/Plack-Middleware-Session/commit/1fbfbb355e34e7f4b3906f66cf958cedadd2b9be.patch","tags":["patch","fix"]},{"url":"https://security.metacpan.org/docs/guides/random-data-for-security.html","tags":["web","report"]},{"url":"http://www.openwall.com/lists/oss-security/2025/07/16/4","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-40923","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-868p-jhqw-wrgr"},{"url":"https://cpan.org/modules","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40923.json","tags":["advisory"]},{"url":"https://github.com/plack/Plack-Middleware-Session","tags":["package"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2025-40923","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2025-40923","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-40923","tags":["report"]},{"url":"https://lists.security.metacpan.org/cve-announce/msg/31223483/","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2025-40923","title":"Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely","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.","status":"published","published":"2025-07-16T13:05:03.782Z","modified":"2025-11-04T21:10:20.704Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"high","assessor":"adp"}],"cwes":["CWE-340","CWE-338"],"updated_at":"2026-11-02T14:32:34.773122Z"}],"euvd":[{"id":"EUVD-2025-21693","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.","status":"published","published":"2025-07-16T13:05:03Z","modified":"2025-11-04T21:10:20Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"high"}],"updated_at":"2026-11-02T19:49:21.645169Z"}],"ghsa":[{"id":"GHSA-868p-jhqw-wrgr","title":"Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely.\n\nThe...","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.","status":"published","published":"2025-07-16T15:32:32Z","modified":"2025-11-05T00:32:25Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"high"}],"cwes":["CWE-338"],"updated_at":"2026-11-02T15:04:39.50413Z"}],"nvd":[{"id":"CVE-2025-40923","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.","status":"published","published":"2025-07-16T13:15:23.997Z","modified":"2026-06-17T09:22:17.947Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"high","assessor":"secondary"}],"cwes":["CWE-338","CWE-340"],"updated_at":"2026-11-02T14:11:18.782156Z"}],"osv":[{"id":"CVE-2025-40923","title":"Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely","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.","status":"published","published":"2025-07-16T13:05:03.782Z","modified":"2026-10-28T02:30:43.414836481Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"high"}],"cwes":["CWE-338","CWE-340"],"updated_at":"2026-11-02T15:44:49.394967Z"},{"id":"DEBIAN-CVE-2025-40923","description":"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 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.  Predicable session ids could allow an attacker to gain access to systems.","status":"published","published":"2025-07-16T13:15:23.997Z","modified":"2026-09-01T20:05:52.260908231Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"high"}],"updated_at":"2026-11-02T15:45:46.998514Z"},{"id":"UBUNTU-CVE-2025-40923","description":"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 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. Predicable session ids could allow an attacker to gain access to systems.","status":"published","published":"2025-07-16T13:15:00Z","modified":"2026-01-20T18:57:40.90074Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"high"}],"updated_at":"2026-11-02T16:55:46.53147Z"}]}}