Affected versions of MISP serve uploaded SVG images inline without a restrictive browser sandbox.


The commit explains that SVG files are XML documents rather than passive bitmap images. While scripts inside SVG do not execute when the SVG is rendered through a normal <img>, they can execute when the SVG is navigated to directly or embedded as a document. In that case, malicious <script> elements, event handlers, or javascript: URLs execute on the MISP origin with the viewer’s session.


The affected use cases include:



 - organisation SVG logos;
 - event-report SVG pictures.






Importantly, the vulnerable behavior is on the serve path, not merely the upload path: the patch notes that a malicious SVG uploaded while SVG support was enabled could remain dangerous even after uploads were later disabled.



Version affected: ≤2.5.45
Advisories

No advisories yet.

Fixes

Solution

A new sandboxInlineFile() method is added to RestResponseComponent. When a file is served inline (download=false) and its type is SVG (svg, svgz, or image/svg+xml), the response is augmented with a Content-Security-Policy header containing the sandbox directive (which assigns an opaque origin and disables script execution, plugins, and form submission) along with restrictive default-src, style-src, img-src, and font-src directives that still permit rendering of inline styles, embedded raster images, and data: fonts. An X-Content-Type-Options: nosniff header is also set. The method is invoked from both the generic sendFile() path and the org-logo endpoint. The enable_svg_logos setting description is updated to warn administrators that SVG files remain XML documents and should be left disabled unless required.


Workaround

No workaround given by the vendor.

History

Mon, 14 Sep 2026 21:00:00 +0000

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

Mon, 14 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Mon, 14 Sep 2026 13:15:00 +0000

Type Values Removed Values Added
Description Affected versions of MISP serve uploaded SVG images inline without a restrictive browser sandbox. The commit explains that SVG files are XML documents rather than passive bitmap images. While scripts inside SVG do not execute when the SVG is rendered through a normal <img>, they can execute when the SVG is navigated to directly or embedded as a document. In that case, malicious <script> elements, event handlers, or javascript: URLs execute on the MISP origin with the viewer’s session. The affected use cases include:  - organisation SVG logos;  - event-report SVG pictures. Importantly, the vulnerable behavior is on the serve path, not merely the upload path: the patch notes that a malicious SVG uploaded while SVG support was enabled could remain dangerous even after uploads were later disabled. Version affected: ≤2.5.45
Title MISP: Stored XSS via Inline-Served SVG Organisation Logos and Report Pictures
Weaknesses CWE-693
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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: CIRCL

Published:

Updated: 2026-09-14T13:58:30.297Z

Reserved: 2026-09-14T13:02:53.577Z

Link: CVE-2026-90957

cve-icon Vulnrichment

Updated: 2026-09-14T13:58:24.824Z

cve-icon NVD

Status : Received

Published: 2026-09-14T13:19:32.907

Modified: 2026-09-14T14:17:21.067

Link: CVE-2026-90957

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-14T20:30:08Z

Weaknesses