CVE-2026-91021 CVE-2026-91021
Attackers with note-authoring privileges can inject JavaScript into shared notes, executing code for other users including administrators.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-91021?
CVE-2026-91021 is a medium-severity cross-site scripting vulnerability in Trilium Trillium Notes, published on 14 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Trilium Notes, version v0.103.0 and earlier, contains a stored cross-site scripting (XSS) vulnerability in the share renderer for webView notes due to improper HTML escaping of user-controlled #webViewSrc values. This vulnerability allows attackers with note-authoring privileges to inject arbitrary JavaScript that executes for any user who opens the shared note, including administrators.
Weakness: CWE-79
Which versions are affected by CVE-2026-91021?
How do I fix CVE-2026-91021?
No fix has been published for CVE-2026-91021 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-2026-91021 being exploited?
There is no known exploitation of CVE-2026-91021 in the wild and no public exploit code.
Sources
Also known as GHSA-g94c-cfqp-6xq2.