CVE-2026-17011 Nexter Blocks < 5.0.2 - Contributor+ Stored CSS Injection
Contributors can inject arbitrary CSS via REST endpoints, enabling site-wide defacement and UI redressing in Nexter Blocks.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-17011?
CVE-2026-17011 is a low-severity cross-site scripting vulnerability in Unknown Nexter Blocks, published on 9 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
The Nexter Blocks WordPress plugin before 5.0.2 does not restrict who can save global CSS through one of its REST endpoints, allowing users with at least the Contributor role to store arbitrary CSS that is rendered site-wide on the front end, enabling defacement, content hiding, and UI redressing.
Weakness: CWE-345
Which versions are affected by CVE-2026-17011?
How do I fix CVE-2026-17011?
No fix has been published for CVE-2026-17011 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-2026-17011 being exploited?
There is no known exploitation of CVE-2026-17011 in the wild and no public exploit code.
Sources
Also known as GHSA-gf2c-5g46-3crp.