VULNERABILITY INTELLIGENCE

CVE-2026-3255

CVSS score6.5 MEDIUM
EPSS probability0.46%
CISA KEVNot currently listed
Published2026-02-27
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

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.

Weakness classification

  • CWE-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
  • CWE-340: Generation of Predictable Numbers or Identifiers

Primary references