CVE-2026-54395

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.

PUBLISHED Reserved 2026-06-12 | Published 2026-06-12 | Updated 2026-06-15 | Assigner CIRCL

Problem types

CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')

Product status

Credits

Jeroen Pinoy finder

Andras Iklody remediation developer

References

github.com/...ommit/b865deb036ca82dab272be260798f562034ba9ae patch

cve.org (CVE-2026-54395)

nvd.nist.gov (CVE-2026-54395)

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