What’s Vulnerable › Vulnerabilities

CVE-2026-8503: Apache::Session::Generate::SHA256 versions before 1.3.19 for Perl create insecure session ids

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-15 · updated 2026-10-26
• Weakness: CWE-338

Description

Apache::Session::Generate::SHA256 versions before 1.3.19 for Perl create insecure session ids. Apache::Session::Generate::SHA256 generated session ids insecurely. The default session id generator returns a SHA-256 hash of the built-in rand() function, the epoch time, and the PID, that is hashed again. These are predictable, low-entropy sources. Predicable session ids could allow an attacker to gain access to systems. Note that version 1.3.19 has a fallback without warning to use insecure session generation method if the call to Crypt::URandom::urandom fails. However, this is unlikely as Crypt::URandom is a hardcoded requirement of the module. This issue is similar to CVE-2025-40931 for Apache::Session::Generate::MD5.

Affected products

• GUIMARD Apache::Session::Generate::Sha256: before 1.3.19 — fixed in 1.3.19

How to fix

Upgrade to a fixed version: GUIMARD Apache::Session::Generate::Sha256 1.3.19. Check the vendor advisory for mitigations.

References

• https://github.com/LemonLDAPNG/Apache-Session-Browseable/commit/cc915cbbd266776eec3dd8bf4748b15fa827dbd0.patch
• https://metacpan.org/release/GUIMARD/Apache-Session-Browseable-1.3.19/changes
• https://metacpan.org/release/GUIMARD/Apache-Session-Browseable-1.3.19/diff/GUIMARD/Apache-Session-Browseable-1.3.18#lib/Apache/Session/Generate/SHA256.pm
• https://www.cve.org/CVERecord?id=CVE-2025-40931
• https://www.cve.org/CVERecord?id=CVE-2025-40932

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