CVE-2026-53693 MISP BSimVis stored cross-site scripting in tag and cluster rendering paths via unescaped tag metadata and UI labels
Attackers can inject malicious scripts via tag metadata in MISP BSimVis, leading to arbitrary JavaScript execution in victim browsers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-53693?
CVE-2026-53693 is a medium-severity cross-site scripting vulnerability in misp bsimvis, published on 10 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A stored cross-site scripting vulnerability existed in MISP BSimVis tag rendering code. Several client-side rendering paths interpolated tag names, collection names, entity identifiers, cluster names, and tag metadata directly into HTML, HTML attributes, inline JavaScript event handlers, and CSS style values without context-appropriate escaping. The patch adds shared escaping helpers for HTML, attributes, JavaScript strings, and CSS color validation, then applies them across tag badges, tooltips, context menus, cluster cards, autocomplete suggestions, and dynamically inserted tag cards.
An attacker able to create or influence stored tag or metadata values could inject a crafted payload that is later rendered in another user’s browser. Successful exploitation could execute arbitrary JavaScript in the victim’s session when they view affected BSimVis pages, potentially allowing the attacker to perform actions as the victim, read data available to the victim, or alter displayed application content.
This issue affects MISP bsimvis: through v0.2.0.
Which versions are affected by CVE-2026-53693?
How do I fix CVE-2026-53693?
No fix has been published for CVE-2026-53693 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-2026-53693 being exploited?
There is no known exploitation of CVE-2026-53693 in the wild and no public exploit code.
Sources
Also known as GHSA-m277-g9rj-mm6h.