CVE-2026-52777 YesWiki: Authenticated PHP Object Injection in BazarImportAction via unserialize
Authenticated attackers can achieve code execution in YesWiki via unsafe deserialization in the BazarImportAction component.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-52777?
CVE-2026-52777 is a critical unsafe deserialization vulnerability in yeswiki, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
YesWiki is a wiki system written in PHP. Prior to version 4.6.6, there is an authenticated PHP object injection vulnerability in BazarImportAction via unserialize. This issue has been patched in version 4.6.6.
Which versions are affected by CVE-2026-52777?
2 open source packages ship an affected version, including yeswiki/yeswiki.
| Package | Affected | Fixed in |
|---|---|---|
yeswiki/yeswiki Packagist | All versions | 4.6.6 |
yeswiki/yeswiki Packagist | All versions | 4.6.6 |
How do I fix CVE-2026-52777?
Upgrade yeswiki/yeswiki to 4.6.6 or later.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-52777 being exploited?
There is no known exploitation of CVE-2026-52777 in the wild and no public exploit code.
Sources
Also known as GHSA-9369-69wj-7m2f.