{"id":"CVE-2026-3256","title":"HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids.\n\nHTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, t…","summary":"HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids.\n\nHTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, t…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-338","CWE-340"],"published":"2026-03-28","updated":"2026-06-29","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-3256","references":[{"url":"https://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/MD5.pm","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/SHA1.pm","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/TOKUHIROM/http-session-0.54/changes","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://security.metacpan.org/docs/guides/random-data-for-security.html","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"http://www.openwall.com/lists/oss-security/2026/03/28/5","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.0053,"epssPercentile":0.43599,"ingestedAt":"2026-06-29T13:24:34.817Z","slug":"CVE-2026-3256","body":"## Overview\n\nHTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids.\n\nHTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, the high resolution 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\nThe distribution includes HTTP::session::ID::MD5 which contains a similar flaw, but uses the MD5 hash instead.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}