MISP: Stored XSS via Inline-Served SVG Organisation Logos and Report Pictures
Summary
| CVE | CVE-2026-90957 |
|---|---|
| State | PUBLISHED |
| Assigner | CIRCL |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-14 13:19:32 UTC |
| Updated | 2026-09-14 14:17:21 UTC |
| 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 |
Risk And Classification
Primary CVSS: v4.0 5.1 MEDIUM from 5a6e4751-2f3f-4070-9419-94fb35b644e8
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/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
Problem Types: CWE-79 | CWE-693 | CWE-79 CWE-79 Improper Neutralization of Input in Web Page ('Cross-site Scripting') | CWE-693 CWE-693 Protection Mechanism Failure
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | Secondary | 5.1 | MEDIUM | 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/E:X/C... |
| 4.0 | CNA | CVSS | 5.1 | MEDIUM | 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 |
CVSS v4.0 Breakdown
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/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
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/MISP/MISP/commit/86496aecc | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Scottish Government - National Cyber Team (en)
CNA: iglocska (en)
CNA: Claude Opus 5 (1M context) (en)
Additional Advisory Data
Solutions
CNA: 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.