CVE-2026-100521 Cotonti through 1.0.0 Reflected XSS via search highlight parameter
Attackers can execute arbitrary JavaScript in victim browsers via a malicious link in the search highlight parameter, potentially leading to account 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-2026-100521?
CVE-2026-100521 is a medium-severity cross-site scripting vulnerability in Cotonti, published on 26 Sep 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
Cotonti through 1.0.0 contains a reflected cross-site scripting vulnerability in the search plugin highlight parameter that performs no HTML or JavaScript escaping. Attackers can craft malicious links with injected JavaScript in the highlight parameter that executes in the browser of any visitor who opens the link, including administrators.
Weakness: CWE-79
Which versions are affected by CVE-2026-100521?
How do I fix CVE-2026-100521?
No fix has been published for CVE-2026-100521 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-2026-100521 being exploited?
There is no known exploitation of CVE-2026-100521 in the wild and no public exploit code.
Sources
Also known as GHSA-9chp-6f7w-99jg.