CVE-2025-15678 Nexter Blocks < 5.0.2 - Author+ Stored XSS via SVG Upload
Attackers with upload privileges can inject malicious JavaScript via SVG files, leading to stored XSS in Nexter Blocks.
- 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-2025-15678?
CVE-2025-15678 is a medium-severity cross-site scripting vulnerability in Unknown Nexter Blocks, published on 6 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 Nexter Blocks WordPress plugin before 5.0.2 does not sanitize uploaded SVG files and allows SVG uploads for any user able to upload files (Author by default), allowing them to upload a file containing malicious JavaScript that executes when the file is accessed, leading to Stored Cross-Site Scripting.
Weakness: CWE-79
Which versions are affected by CVE-2025-15678?
How do I fix CVE-2025-15678?
No fix has been published for CVE-2025-15678 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-2025-15678 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-15678 exists.
Sources
Also known as GHSA-mg54-xc87-q8w3.