CVE-2026-3256 | HTTP::Session versions before 0.54 for Perl defaults to usin… | CVSS 9.8 CRITICAL

Description

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.

Metadata

CVE ID: CVE-2026-3256
State: PUBLISHED
Assigner: CPANSec
Reserved: 2026-02-26 11:59 UTC
Published: 2026-03-28 18:52 UTC
Last updated: 2026-06-29 06:50 UTC
Primary CWE: CWE-340
CWE-340 Generation of Predictable Numbers or Identifiers
Vendor / Product: KTAT / HTTP::Session
Sources: cve.org · NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC — CISA Coordinator

Exploitation: none
Automatable: yes
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
KTAT	HTTP::Session	—	0 < 0.54

Weakness (CWE)

CWE	Source	Description
CWE-338	cna	CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator
CWE-340	cna	CWE-340 Generation of Predictable Numbers or Identifiers

CVSS scores (1)

Score	Severity	Version	Source	Vector
9.8	CRITICAL	3.1	adp	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References (4)