Vulnerability in Tokuhirom HTTP\
CVE-2026-3255
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (39.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Tokuhirom HTTP\ — versions \
- Tokuhirom Http::session2 — versions 0
- Tokuhirom Http\:\:session2
Weakness classification (CWE)
References
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (Issue Tracking)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (Issue Tracking)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes, Release Notes)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (Patch, patch)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-3255?
- CVE-2026-3255 is a medium-severity vulnerability in Tokuhirom HTTP\, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 6.5/10. Published 2026-02-27.
- How severe is CVE-2026-3255?
- Medium severity. CVSS v3 base score is 6.5 out of 10.