CVE-2026-15383 Blog Floating Button <= 1.4.20 - Unauthenticated Stored XSS via User-Agent Header
Unauthenticated attackers can inject malicious scripts via the User-Agent header, which execute in administrator sessions, potentially leading to site 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
- None listed
What is CVE-2026-15383?
CVE-2026-15383 is a medium-severity cross-site scripting vulnerability in Unknown Blog Floating Button, published on 3 Aug 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 Blog Floating Button WordPress plugin through 1.4.20 does not sanitize or escape the visitor User-Agent header, which it stores through an unauthenticated tracking REST endpoint and later renders unescaped in an administrator report page. This allows an unauthenticated attacker to store a malicious script that executes in the session of any administrator who views the access report, leading to site takeover.
Weakness: CWE-79
Which versions are affected by CVE-2026-15383?
How do I fix CVE-2026-15383?
No fix has been published for CVE-2026-15383 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-2026-15383 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15383 exists.
Sources
Also known as GHSA-r7c9-cm4j-g8qq.