CVE-2026-52771 YesWiki: Second-Order SQL Injection in Page Delete API via Unescaped Page Tag (`ApiController::deletePage`)
A low-privilege user can execute arbitrary SQL queries via second-order injection in the page delete API, allowing data exfiltration or modification.
- 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-2026-52771?
CVE-2026-52771 is a high-severity SQL 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. From version 4.2.0 to before version 4.6.6, ApiController::deletePage() interpolates a page tag retrieved from the database into a DELETE FROM …_links WHERE to_tag = '$tag' query without escaping. The page tag is attacker-controlled — the POST /api/pages/{tag} API accepts arbitrary URL-encoded values, including single quotes, and stores them. A low-privilege authenticated user can therefore create a page whose tag is a SQL fragment, make the page non-orphaned via the standard {{include page="…"}} link mechanism, and then invoke the delete endpoint to execute arbitrary SQL inside the wiki database - including time-based blind data exfiltration from any table. This issue has been patched in version 4.6.6.
Weakness: CWE-89
Which versions are affected by CVE-2026-52771?
2 open source packages ship an affected version, including yeswiki/yeswiki.
| Package | Affected | Fixed in |
|---|---|---|
yeswiki/yeswiki Packagist | From 4.2.0 | 4.6.6 |
yeswiki/yeswiki Packagist | From 4.2.0 | 4.6.6 |
How do I fix CVE-2026-52771?
Upgrade yeswiki/yeswiki to 4.6.6 or later.
Use parameterised queries everywhere and never build SQL by joining strings. Upgrade affected software first; a web application firewall only buys time. More about SQL injection.
Is CVE-2026-52771 being exploited?
There is no known exploitation of CVE-2026-52771 in the wild and no public exploit code.
Sources
Also known as GHSA-8f2v-2qhj-gfwg.