{"id":"CVE-2025-40926","state":"PUBLISHED","title":"Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely","description":"Plack::Middleware::Session::Simple versions before 0.05 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\nPredictable session ids could allow an attacker to gain access to systems.\n\nPlack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923.","publishedAt":"2026-03-05T01:24:34.151Z","updatedAt":"2026-04-21T02:42:17.296Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"CISA-ADP"},"assigner":"CPANSec","products":["KAZEBURO Plack::Middleware::Session::Simple"],"affected":[{"vendor":"KAZEBURO","product":"Plack::Middleware::Session::Simple","packageName":"Plack-Middleware-Session-Simple","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"0.05","versionType":"custom"}],"collectionURL":"https://cpan.org/modules","programFiles":["lib/Plack/Middleware/Session/Simple.pm"],"programRoutines":[{"name":"Plack::Middleware::Session::Simple::sid_generator"}],"repo":"https://github.com/kazeburo/Plack-Middleware-Session-Simple"}],"references":["https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.04/source/lib/Plack/Middleware/Session/Simple.pm#L43","https://github.com/kazeburo/Plack-Middleware-Session-Simple/pull/4","https://github.com/kazeburo/Plack-Middleware-Session-Simple/commit/760bb358b8f53e52cf415888a4ac858fd99bb24e.patch","https://www.cve.org/CVERecord?id=CVE-2025-40923","https://security.metacpan.org/docs/guides/random-data-for-security.html","https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.05/changes"],"weaknesses":["CWE-340","CWE-338"],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/40xxx/CVE-2025-40926.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40926","state":"PUBLISHED","datePublished":"2026-03-05T01:24:34.151Z","dateUpdated":"2026-04-21T02:42:17.296Z","assignerShortName":"CPANSec","assignerOrgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","dateReserved":"2025-04-16T09:05:34.362Z"},"containers":{"cna":{"title":"Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely","descriptions":[{"lang":"en","value":"Plack::Middleware::Session::Simple versions before 0.05 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\nPredictable session ids could allow an attacker to gain access to systems.\n\nPlack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923."}],"affected":[{"vendor":"KAZEBURO","product":"Plack::Middleware::Session::Simple","packageName":"Plack-Middleware-Session-Simple","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"0.05","versionType":"custom"}],"collectionURL":"https://cpan.org/modules","programFiles":["lib/Plack/Middleware/Session/Simple.pm"],"programRoutines":[{"name":"Plack::Middleware::Session::Simple::sid_generator"}],"repo":"https://github.com/kazeburo/Plack-Middleware-Session-Simple"}],"references":[{"url":"https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.04/source/lib/Plack/Middleware/Session/Simple.pm#L43"},{"url":"https://github.com/kazeburo/Plack-Middleware-Session-Simple/pull/4","tags":["issue-tracking"]},{"url":"https://github.com/kazeburo/Plack-Middleware-Session-Simple/commit/760bb358b8f53e52cf415888a4ac858fd99bb24e.patch","tags":["patch"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-40923","tags":["vendor-advisory","related","vdb-entry"]},{"url":"https://security.metacpan.org/docs/guides/random-data-for-security.html","tags":["technical-description"]},{"url":"https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.05/changes","tags":["release-notes"]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-340","description":"CWE-340 Generation of Predictable Numbers or Identifiers","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-338","description":"CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"CPANSec","orgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","dateUpdated":"2026-03-11T23:25:24.779Z"},"solutions":[{"lang":"en","value":"Users are advised to upgrade to version 0.05 or later."}],"source":{"discovery":"UNKNOWN"},"workarounds":[{"lang":"en","value":"Users are advised to change the sid_generator attribute of Plack::Middleware::Session::Simple to a function that returns a securely generated session id based on a secure source of entropy from the system.\n\nUsers may consider using Plack::Middleware::Session version 0.35 or later."}],"x_generator":{"engine":"cpansec-cna-tool 0.1"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":9.8,"attackVector":"NETWORK","baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-03-05T16:28:14.069463Z","id":"CVE-2025-40926","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-21T02:42:17.296Z"}}]}}}