CVE-2026-4186 UEditor JSONP Callback controller.php cross site scripting
Remote attackers can execute arbitrary scripts via the JSONP callback parameter in UEditor, affecting unsupported versions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-4186?
CVE-2026-4186 is a medium-severity cross-site scripting vulnerability in UEditor, published on 15 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
A vulnerability was determined in UEditor up to 1.4.3.2. This issue affects some unknown processing of the file php/controller.php?action=uploadimage of the component JSONP Callback Handler. This manipulation of the argument callback causes cross site scripting. The attack can be initiated remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way. This vulnerability only affects products that are no longer supported by the maintainer.
Which versions are affected by CVE-2026-4186?
How do I fix CVE-2026-4186?
No fix has been published for CVE-2026-4186 yet. Limit exposure of the affected software until one is available.
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-2026-4186 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4186 exists.
Sources
Also known as GHSA-4p5h-fxjc-527w.