HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids (CVE-2026-3256) | HOL Guard CVE

Critical · CVSS 9.8CVE-2026-3256

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

Answer in brief

CVE-2026-3256 records a Critical severity (CVSS 9.8) vulnerability in HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids. The current sources do not mark it as known exploited. The current feed maps KTAT/HTTP::Session (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Mar 28, 2026Updated Jun 29, 2026Source checked Sep 19, 2026First seen by HOL Jun 29, 2026Material review Jun 29, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps KTAT/HTTP::Session (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
KTAT/HTTP::Sessiongeneric	>=0 <0.54	0.54

Recommended response

Check inventory. Check lockfiles and deployed manifests for KTAT/HTTP::Session.
Review the reported fix. Update KTAT/HTTP::Session to 0.54 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Mar 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Jun 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jun 29, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.