CVE-2026-86833 MetForm < 4.3.1 - Unauthenticated HTML Injection in Notification Emails via Field Shortcodes
Unauthenticated attackers can inject HTML into MetForm notification emails, potentially leading to XSS attacks against administrators or users.
- 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
- None listed
What is CVE-2026-86833?
CVE-2026-86833 is a medium-severity cross-site scripting vulnerability in Unknown MetForm, published on 7 Oct 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
The MetForm WordPress plugin before 4.3.1 does not sanitize or escape submitted form-field values before inserting them into the HTML body of its email notifications, allowing unauthenticated attackers to inject arbitrary markup into the administrator and submitter notification emails the site sends.
Weakness: CWE-74
Which versions are affected by CVE-2026-86833?
How do I fix CVE-2026-86833?
No fix has been published for CVE-2026-86833 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-2026-86833 being exploited?
There is no known exploitation of CVE-2026-86833 in the wild and no public exploit code.
Sources
Also known as GHSA-fv77-662p-ggvf.