CVE-2026-52773 Reflected XSS via Unescaped Archived-Revision `time` Parameter in `handlers/page/show.php` in YesWiki
Reflected XSS in YesWiki allows attackers to execute arbitrary JavaScript via the time parameter, potentially leading to account takeover.
- 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-2026-52773?
CVE-2026-52773 is a medium-severity cross-site scripting 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. From version 4.1.0 to before version 4.6.6, YesWiki's archived-revision view reflects the time GET parameter into a hidden HTML input in handlers/page/show.php without escaping. Because MySQL coerces malformed DATETIME strings, an attacker can append HTML or JavaScript to a valid archived revision timestamp, still load that archived revision, and execute arbitrary JavaScript in the victim's browser. The vulnerable form is only rendered when the victim can both read and edit the target page. In restricted deployments this requires a victim with read and write access to that page. On a default doryphore 4.6.5 install, public pages such as PagePrincipale were editable anonymously during validation, so the issue can also affect unauthenticated visitors in that configuration. This issue has been patched in version 4.6.6.
Weakness: CWE-80
Which versions are affected by CVE-2026-52773?
2 open source packages ship an affected version, including yeswiki/yeswiki.
| Package | Affected | Fixed in |
|---|---|---|
yeswiki/yeswiki Packagist | From 4.1.0 | 4.6.6 |
yeswiki/yeswiki Packagist | From 4.1.0 | 4.6.6 |
How do I fix CVE-2026-52773?
Upgrade yeswiki/yeswiki to 4.6.6 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-52773 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52773 exists.
Public exploit code: 1 Nuclei template.
Sources
Also known as GHSA-35f3-pg38-486f.