CVE-2026-91011 EWWW Image Optimizer < 8.7.7 - Author+ Stored XSS via Image Class Attribute Backreference Expansion
Authenticated authors can inject stored JavaScript via image attributes, leading to code execution in victim browsers.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-91011?
CVE-2026-91011 is a medium-severity cross-site scripting vulnerability in Unknown EWWW Image Optimizer, published on 17 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
The EWWW Image Optimizer WordPress plugin before 8.7.7 does not properly escape image attribute values when it rewrites page output, allowing authenticated users with author-level access and above to inject arbitrary JavaScript that is stored in published content and executes in the browser of any user who later views the affected page.
Weakness: CWE-79
Which versions are affected by CVE-2026-91011?
How do I fix CVE-2026-91011?
No fix has been published for CVE-2026-91011 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-2026-91011 being exploited?
There is no known exploitation of CVE-2026-91011 in the wild and no public exploit code.
Sources
Also known as GHSA-5c4g-pv82-qr56.