CVE-2026-81571 Brave Popup Builder < 0.8.8 - Unauthenticated Arbitrary Shortcode Execution via UTM Parameter
Unauthenticated attackers can execute arbitrary shortcodes server-side via a URL parameter, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-81571?
CVE-2026-81571 is a medium-severity code injection vulnerability in Unknown Brave, published on 2 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The Brave WordPress plugin before 0.8.8 does not prevent a URL parameter used to pre-fill a form field from being passed to WordPress's shortcode engine, allowing unauthenticated attackers to have arbitrary shortcodes registered on the site executed server-side.
Weakness: CWE-74
Which versions are affected by CVE-2026-81571?
How do I fix CVE-2026-81571?
No fix has been published for CVE-2026-81571 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-81571 being exploited?
There is no known exploitation of CVE-2026-81571 in the wild and no public exploit code.
Sources
Also known as GHSA-mhhc-49mj-h4mm.