CVE-2025-40926

9.8 CRITICAL
Published: March 05, 2026 Modified: March 12, 2026
View on NVD

Description

Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely. The default 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. Predictable session ids could allow an attacker to gain access to systems. Plack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/kazeburo/Plack-Middleware-Session-Simple/pull/4
Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
Issue Tracking Patch
https://security.metacpan.org/docs/guides/random-data-for-security.html
Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
Third Party Advisory
https://www.cve.org/CVERecord?id=CVE-2025-40923
Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
Third Party Advisory

6 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.8 / 10.0
EPSS (Exploit Probability)
0.1%
20th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

kazeburo