CVE-2026-3256
HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids.
HTTP::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.
The distribution includes HTTP::session::ID::MD5 which contains a similar flaw, but uses the MD5 hash instead.
Package Versions Affected
Automatically patch vulnerabilities without upgrading
CVSS Version



Related Resources
References
http://www.openwall.com/lists/oss-security/2026/03/28/5, https://cpan.org/modules, https://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/MD5.pm, https://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/SHA1.pm, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3256.json, https://metacpan.org/release/TOKUHIROM/http-session-0.54/changes, https://nvd.nist.gov/vuln/detail/CVE-2026-3256, https://github.com/tokuhirom/http-session, https://security.metacpan.org/docs/guides/random-data-for-security.html