CVE-2026-52762 YesWiki: Authenticated (Admin) Server-Side Template Injection to Remote Code Execution via Bazar Semantic Templates
An authenticated administrator can achieve remote code execution by injecting Twig expressions into semantic templates in YesWiki.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-52762?
CVE-2026-52762 is a high-severity code injection vulnerability in yeswiki, published on 4 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
YesWiki is a wiki system written in PHP. Prior to version 4.6.6, YesWiki Bazar contains a stored Server-Side Template Injection (SSTI) vulnerability in the semantic template feature that can be escalated to confirmed Remote Code Execution (RCE). An authenticated administrator can place arbitrary Twig expressions into the Semantic template (Twig) field (bn_sem_template), and that content is later executed server-side when public semantic endpoints are requested. This issue has been patched in version 4.6.6.
Weakness: CWE-1336
Which versions are affected by CVE-2026-52762?
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-2026-52762?
Upgrade yeswiki/yeswiki to 4.6.6 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-52762 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52762 exists.
Sources
Also known as GHSA-65p8-9433-jpcp.