Vulnerability in Guimard Apache\
CVE-2026-8503
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (31.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.001
Affected products
- Guimard Apache\ — versions \
- Guimard Apache::session::generate::sha256 — versions 0
- Guimard Apache\:\:session\:\:generate\:\:sha256
Weakness classification (CWE)
References
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes, Release Notes)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (Product)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (Patch, patch)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (related, Third Party Advisory)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (related, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-8503?
- CVE-2026-8503 is a medium-severity vulnerability in Guimard Apache\, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 6.5/10. Published 2026-05-15.
- How severe is CVE-2026-8503?
- Medium severity. CVSS v3 base score is 6.5 out of 10.