CVE-2026-3256CWE-338CWE-340

HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids

Critical · published March 28, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
52.8
In the wild
Unconfirmed
What it is

HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids.

HTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, the high resolution 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.

The distribution includes HTTP::session::ID::MD5 which contains a similar flaw, but uses the MD5 hash instead.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00706 · 52.8th percentile
Weaknesses
CWE-338 · Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG); CWE-340 · Generation of Predictable Numbers or Identifiers
Published
2026-03-28T18:52Z
EPSS history
Timeline
  • 28 MAR 18:52Z
    HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids
    cvelistv5