CVE-2026-3256criticalCWE-338CWE-340

CVE-2026-3256: critical vulnerability in KTAT HTTP::Session

HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids

Published · Updated

28Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 9.8epss 0.7%
exploitation probability
0.7%top 48% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
KTAT · HTTP::Session
References
https://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/MD5.pmhttps://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/SHA1.pmhttps://metacpan.org/release/TOKUHIROM/http-session-0.54/changeshttps://security.metacpan.org/docs/guides/random-data-for-security.htmlhttp://www.openwall.com/lists/oss-security/2026/03/28/5