CVE-2026-54395

MEDIUM EPSS 16.8%

Published Jun 12, 20262w ago · Modified Jun 17, 20262w ago

5.3 CVSS 4.0

Medium

Published Jun 12, 2026 2w ago

Last Modified Jun 17, 2026 2w ago

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 Details

Base Score

5.3

Exploitability

—

Impact

—

Vector string

CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector Network

Attack Complexity Low

Privileges Required Low

User Interaction None

Scope X

Threat Intelligence

EPSS Exploit Probability

16.8% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

References 1

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

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.