Deserialization in Wolfssl

CVE-2026-5507

When restoring a session from cache, a pointer from the serialized session data is used in a free operation without validation. An attacker who can poison the session cache could trigger an arbitrary free. Exploitation requires the ability to inject a crafted session into the cache and for the application to call specific session restore APIs.

Vulnerability class: Insecure Deserialization

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (13.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 13.5% 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-2026-5507: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-5507?
CVE-2026-5507 is a medium-severity vulnerability in Wolfssl, classified under Deserialization of Untrusted Data. CVSS score: 4.0/10. Published 2026-04-09.
How severe is CVE-2026-5507?
Medium severity. CVSS v3 base score is 4.0 out of 10.