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Vulnerability · Published May 15, 2026 · Assigned by CPANSec

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

Medium 6.5

In plain English

A medium-severity security flaw in Apache::Session::Generate::SHA256 from GUIMARD. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.2%top 84.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12libapache-session-browseable-perl1.3.11-3+deb12u1DEBIAN-CVE-2026-8503
Debian:13libapache-session-browseable-perl1.3.16-1+deb13u1DEBIAN-CVE-2026-8503
Debian:14libapache-session-browseable-perl1.3.19-1DEBIAN-CVE-2026-8503
Ubuntu:22.04:LTSlibapache-session-browseable-perlno fix listedUBUNTU-CVE-2026-8503
Ubuntu:24.04:LTSlibapache-session-browseable-perlno fix listedUBUNTU-CVE-2026-8503
Ubuntu:25.10libapache-session-browseable-perlno fix listedUBUNTU-CVE-2026-8503
Ubuntu:26.04:LTSlibapache-session-browseable-perlno fix listedUBUNTU-CVE-2026-8503
Ubuntu:26.10libapache-session-browseable-perlno fix listedUBUNTU-CVE-2026-8503

Affected products (as reported)

VendorProductVersions
GUIMARD Apache::Session::Generate::SHA256 0 – before 1.3.19

Weakness: CWE-340, CWE-338 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References