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
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| MISP | MISP | unaffected |
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No data.
No data.
No data available yet.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Link | Providers |
|---|---|
| https://github.com/MISP/MISP/commit/adf704e94 |
|
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 |
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| References |
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| Metrics |
cvssV4_0
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Subscriptions
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MITRE
Status: PUBLISHED
Assigner: CIRCL
Published:
Updated: 2026-09-07T12:35:10.174Z
Reserved: 2026-09-07T12:35:06.572Z
Link: CVE-2026-86440
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-07T13:20:43.153
Modified: 2026-09-07T13:20:43.153
Link: CVE-2026-86440
Redhat
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OpenCVE Enrichment
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