Deserialization in TYPO3 Extension "Html5 Video Player Vs. Powermail"

CVE-2026-77138

The extension fails to safely process untrusted client input of an attacker-controlled cookie directly to PHP's unserialize(). A remote, unauthenticated attacker can supply a crafted serialized payload to trigger PHP Object Injection, leading to Remote Code Execution on the TYPO3 server.

Vulnerability class: Insecure Deserialization

Published · last modified .

EPSS exploit prediction

EPSS: 0.007 (52.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.4% 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-2026-77138: held from 0.004 to 0.007.

EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003

Affected products

Weakness classification (CWE)

References