Quick answers
- Is CVE-2026-72583 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-72583 being exploited in the wild.
- How severe is CVE-2026-72583?
- Medium severity, with a CVSS score of 5.4, published 10 August 2026.
- Which products and versions are affected?
- Fastschema through v0.15.1.
- Is there a fix for CVE-2026-72583?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-72583 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-72583?
- Check whether you run Fastschema at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
This is a stored cross-site scripting (XSS) vulnerability in fastschema through v0.15.1 caused by insufficient validation of SVG file uploads. The application attempts to enforce MIME type restrictions via an allow-list, but attackers can bypass this check by uploading an SVG file with embedded malicious JavaScript. The vulnerability requires authentication with low-level privileges to exploit. When another user or administrator views the uploaded SVG file through the application interface, the embedded JavaScript executes in their browser context, potentially allowing session hijacking, credential theft, or other malicious actions. Patches are expected to be available in versions after v0.15.1.
Affected products
- fastschema fastschema through v0.15.1
Timeline
- 2026-08-10: disclosed: CVE-2026-72583 published