Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Tokuhirom | Http\ | < 1.12, \ |
Related Weaknesses (CWE)
References
- https://github.com/tokuhirom/HTTP-Session2/commit/9cfde4d7e0965172aef5dcfa3b03bbPatch
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.01/source/lib/HTTP/SessioIssue Tracking
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.11/source/lib/HTTP/SessioIssue Tracking
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.12/changesRelease Notes
- http://www.openwall.com/lists/oss-security/2026/02/27/12Mailing ListThird Party Advisory
FAQ
What is CVE-2026-3255?
CVE-2026-3255 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 ra...
How severe is CVE-2026-3255?
CVE-2026-3255 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-3255?
Check the references section above for vendor advisories and patch information. Affected products include: Tokuhirom Http\.