CVE-2026-90957 MISP: Stored XSS via Inline-Served SVG Organisation Logos and Report Pictures
Attackers can execute arbitrary scripts on the MISP origin via malicious SVG files, potentially stealing user sessions and data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-90957?
CVE-2026-90957 is a medium-severity cross-site scripting vulnerability in MISP, published on 14 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official 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
Which versions are affected by CVE-2026-90957?
How do I fix CVE-2026-90957?
No fix has been published for CVE-2026-90957 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-90957 being exploited?
There is no known exploitation of CVE-2026-90957 in the wild and no public exploit code.
Sources
Also known as GHSA-5mp5-7f8h-r69q.