CVE-2026-5507 Session Cache Restore — Arbitrary Free via Deserialized Pointer
An attacker with session cache access can trigger an arbitrary free via deserialized pointers, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-5507?
CVE-2026-5507 is a medium-severity use after free vulnerability in Wolfssl Wolfssl, published on 9 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-502
Which versions are affected by CVE-2026-5507?
It affects 1 product.
Products include Wolfssl Wolfssl.
How do I fix CVE-2026-5507?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-5507 being exploited?
There is no known exploitation of CVE-2026-5507 in the wild and no public exploit code.
Other vulnerabilities in Wolfssl Wolfssl
Sources
Also known as DEBIAN-CVE-2026-5507, GHSA-f5fh-xmxq-55p9, JLSEC-2026-733, UBUNTU-CVE-2026-5507.