CVE-2026-7635 Deserialization in coreActivity: Activity Logging for WordPress
Unauthenticated attackers can cause persistent denial of service by injecting serialized payloads via User-Agent headers, blocking admin access to logs.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-7635?
CVE-2026-7635 is a high-severity unsafe deserialization vulnerability in gdragon coreActivity: Activity Logging for WordPress, published on 13 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The coreActivity: Activity Logging for WordPress plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.0. This is due to the plugin failing to validate or strip PHP serialization syntax from the User-Agent HTTP header before storing it in the logmeta table, and subsequently calling `maybe_unserialize()` on every retrieved `meta_value` in `query_metas()` without verifying the data was originally serialized by the application. This makes it possible for unauthenticated attackers to inject a crafted PHP serialized payload via the User-Agent header during any logged event (such as a failed login attempt), which, when an administrator views the Logs page, is deserialized and passed to `DeviceDetector::setUserAgent()`, triggering a Fatal TypeError that creates a persistent Denial of Service condition blocking administrator access to the Logs page entirely.
Weakness: CWE-502
Which versions are affected by CVE-2026-7635?
How do I fix CVE-2026-7635?
No fix has been published for CVE-2026-7635 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-7635 being exploited?
There is no known exploitation of CVE-2026-7635 in the wild and no public exploit code.