CVEvulnerability
CVE-2025-40926
9.8 CRITICAL
Official page ↗
- Status
- Modified
- Published
- 2026-03-05
- Last modified
- 2026-06-17
- Assigner
- 9b29abf9-4ab0-4765-b253-1875cd9b441e
- CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
- 9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-338, CWE-340
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.
Affected configurations
• kazeburo plack\ \ (< 0.05)
Related
References
- https://github.com/kazeburo/Plack-Middleware-Session-Simple/commit/760bb358b8f53e52cf415888a4ac858fd99bb24e.patch Patch
- https://github.com/kazeburo/Plack-Middleware-Session-Simple/pull/4 Issue Tracking, Patch
- https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.04/source/lib/Plack/Middleware/Session/Simple.pm#L43 Issue Tracking, Product
- https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.05/changes metacpan.org
- https://security.metacpan.org/docs/guides/random-data-for-security.html Third Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2025-40923 Third Party Advisory