CVE-2026-53693: A stored cross-site scripting vulnerability existed in MISP BSimVis tag rendering code. Several client-side rendering paths interpolated tag names, co...

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.

Metrics

CVSS 4.0

6.9/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.28%

19.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

https://github.com/MISP/bsimvis/commit/7bcd2c2e27647dccdfb71877e905fbb032124a63

Timeline

Published: Jun 10, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-53693?

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.

How severe is CVE-2026-53693?

CVE-2026-53693 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.28% probability of exploitation in the next 30 days.

How do I fix CVE-2026-53693?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.