CVE-2026-66300 SNOMED International Snowstorm reflected XSS
Attackers can execute arbitrary JavaScript in user browsers via crafted links in SNOMED Snowstorm, potentially leading to session hijacking or data theft.
- 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-2026-66300?
CVE-2026-66300 is a low-severity cross-site scripting vulnerability in SNOMED International Snowstorm, published on 4 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
SNOMED International Snowstorm contains a reflected XSS vulnerability within the "Web Route" redirection functionality. An attacker can inject arbitrary JavaScript which will execute upon a target user navigating to a crafted, malicious link. Fixed in 10.12.2 and 10.9.3.
Weakness: CWE-79
Which versions are affected by CVE-2026-66300?
How do I fix CVE-2026-66300?
No fix has been published for CVE-2026-66300 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-2026-66300 being exploited?
There is no known exploitation of CVE-2026-66300 in the wild and no public exploit code.
Sources
Also known as GHSA-hc58-x27q-7xc8.