CVE-2026-3255

medium

Description

HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function. The HTTP::Session2 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. HTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above.

References

https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.12/changes

https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.11/source/lib/HTTP/Session2/Random.pm#L35

https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.01/source/lib/HTTP/Session2/ServerStore.pm#L68

https://github.com/tokuhirom/HTTP-Session2/commit/9cfde4d7e0965172aef5dcfa3b03bb48df93e636.patch

http://www.openwall.com/lists/oss-security/2026/02/27/12

Details

Source: Mitre, NVD

Published: 2026-02-27

Updated: 2026-03-03

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

Severity: Medium