CVE-2026-3256

CRITICAL

HTTP::Session versions through 0.53 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.

CVSS v3.1 Score

9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Published: 3/28/2026Modified: 4/1/2026

Related Intelligence (1)

CRITICALVulnerabilityPOC

NVD CRITICAL: CVE-2026-3256 — HTTP::Session versions through 0.53 for Perl defaults to using insecurely genera...

HTTP::Session versions through 0.53 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 Da

CVE-2026-3256
NIST NVD

References (4)

https://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/MD5.pmProducthttps://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/ID/SHA1.pmProducthttps://security.metacpan.org/docs/guides/random-data-for-security.htmlThird Party Advisoryhttp://www.openwall.com/lists/oss-security/2026/03/28/5Mailing ListThird Party Advisory