Affected versions of MISP insufficiently validate URLs used by dashboard widgets, particularly the Button widget.


The widget's URL is stored configuration controlled by a user. The previous renderer considered a URL safe if it appeared relative or if its parsed hostname matched the configured MISP hostname. That logic failed to reject dangerous schemes and URL forms that browsers normalize differently from PHP's URL parsing.


As a result, values such as javascript: URLs or backslash-based authority forms could reach the generated anchor's href and execute script or navigate to an attacker-controlled origin when another user interacted with the widget. The upstream commit describes the issue as:


“javascript: and backslash URLs reached the href (stored XSS)”.


The fix routes widget URLs through a shared DashboardURLValidator, rejects dangerous schemes, raw backslashes, control characters, and unauthorized absolute origins, and validates the URL both in the widget handler and renderer.

Version affected: ≤2.5.45

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History

Tue, 08 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 07 Sep 2026 14:15:00 +0000

Type Values Removed Values Added
First Time appeared Misp
Misp misp
Vendors & Products Misp
Misp misp

Mon, 07 Sep 2026 12:45:00 +0000

Type Values Removed Values Added
Description Affected versions of MISP insufficiently validate URLs used by dashboard widgets, particularly the Button widget. The widget's URL is stored configuration controlled by a user. The previous renderer considered a URL safe if it appeared relative or if its parsed hostname matched the configured MISP hostname. That logic failed to reject dangerous schemes and URL forms that browsers normalize differently from PHP's URL parsing. As a result, values such as javascript: URLs or backslash-based authority forms could reach the generated anchor's href and execute script or navigate to an attacker-controlled origin when another user interacted with the widget. The upstream commit describes the issue as: “javascript: and backslash URLs reached the href (stored XSS)”. The fix routes widget URLs through a shared DashboardURLValidator, rejects dangerous schemes, raw backslashes, control characters, and unauthorized absolute origins, and validates the URL both in the widget handler and renderer. Version affected: ≤2.5.45
Title MISP Dashboard Button Widget Allows Stored XSS via Unsafe javascript: and Backslash URLs
Weaknesses CWE-20
CWE-79
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: CIRCL

Published:

Updated: 2026-09-08T14:51:34.403Z

Reserved: 2026-09-07T12:35:06.572Z

Link: CVE-2026-86440

cve-icon Vulnrichment

Updated: 2026-09-08T14:51:30.612Z

cve-icon NVD

Status : Undergoing Analysis

Published: 2026-09-07T13:20:43.153

Modified: 2026-09-08T15:18:55.433

Link: CVE-2026-86440

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-07T14:15:16Z

Weaknesses