CVE-2026-3255
HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function.
Does this matter?
Lower severity and a low EPSS score (0.42%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
- EPSS
- 0.42% probability · 35th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-338, CWE-340
- Affected
- tokuhirom/http\
- Source
- 9b29abf9-4ab0-4765-b253-1875cd9b441e
References
- https://github.com/tokuhirom/HTTP-Session2/commit/9cfde4d7e0965172aef5dcfa3b03bb48df93e636.patchPatch
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.01/source/lib/HTTP/Session2/ServerStore.pm#L68Issue Tracking
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.11/source/lib/HTTP/Session2/Random.pm#L35Issue Tracking
- https://metacpan.org/release/TOKUHIROM/HTTP-Session2-1.12/changesRelease Notes
- http://www.openwall.com/lists/oss-security/2026/02/27/12Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.