CVE-2026-3255
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
27/02/2026
Last modified:
28/02/2026
Description
HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function.<br />
<br />
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.<br />
<br />
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.
Impact
References to Advisories, Solutions, and Tools
- https://github.com/tokuhirom/HTTP-Session2/commit/9cfde4d7e0965172aef5dcfa3b03bb48df93e636.patch
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.01/source/lib/HTTP/Session2/ServerStore.pm#L68
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.11/source/lib/HTTP/Session2/Random.pm#L35
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.12/changes
- http://www.openwall.com/lists/oss-security/2026/02/27/12



