VulnerabilityDeferred

CVE-2026-54395

MISP contains a reflected cross-site scripting vulnerability in the UiBeta event index view.

MEDIUM 5.3EPSS 0.26%

Does this matter?

Lower severity and a low EPSS score (0.26%). Track it; it rarely justifies an emergency change on its own.

Description

MISP contains a reflected cross-site scripting vulnerability in the UiBeta event index view. The urlparams value is inserted into an inline JavaScript handler using HTML escaping inside a single-quoted JavaScript string. Because browsers HTML-decode attribute values before JavaScript parsing, a crafted searcheventinfo value can restore encoded quote characters and break out of the JavaScript string. An attacker could craft a malicious URL that, when opened by a victim using the UiBeta event index, executes arbitrary JavaScript in the victim’s browser in the context of the MISP instance. The issue is fixed by encoding the value as a JavaScript string literal with json_encode() before applying HTML escaping at the attribute layer.

CVSS 4.0: 5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.26% probability · 17th percentile
CISA KEV: Not listed
Weakness: CWE-79
Source: 5a6e4751-2f3f-4070-9419-94fb35b644e8

References

https://github.com/MISP/MISP/commit/b865deb036ca82dab272be260798f562034ba9ae

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.