Vulnerability in Aspeer Webdyne::session

CVE-2026-5084

WebDyne::Session versions before 3.003_704 for Perl generate the session id insecurely. The session handler generates the session id from an MD5 hash seeded with a call to the built-in rand() function. The rand function is passed a maximum value based on the process id, the epoch time and the reference address of the object, but this information will have no effect on the overall quality of the seed of the message digest. The rand function is seeded by 32-bits and is predictable. It is considered unsuitable for cryptographic purposes. Predictable session ids could allow an attacker to gain access to systems. Note that WebDyne::Session versions 1.042 and earlier appear to be in separate distributions from WebDyne.

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 (29.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-5084: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-5084?
CVE-2026-5084 is a medium-severity vulnerability in Aspeer Webdyne::session, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 6.5/10. Published 2026-05-11.
How severe is CVE-2026-5084?
Medium severity. CVSS v3 base score is 6.5 out of 10.