XSS in Flintsh Flare
CVE-2026-26993
Flare is a Next.js-based, self-hostable file sharing platform that integrates with screenshot tools. Versions 1.7.0 and below allow users to upload files without proper content validation or sanitization. By embedding malicious JavaScript within an SVG (or other active content formats such as HTML or XML), an attacker can achieve script execution in the context of the application's origin when a victim views the file in “raw” mode. This results in a stored Cross-Site Scripting (XSS) vulnerability that can be exploited to exfiltrate user data. This issue has been fixed in version 1.7.1.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (28.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Flintsh Flare — versions 1.7.1
Weakness classification (CWE)
References
- github.com/FlintSH/Flare/security/advisories/GHSA-q8fp-w6m5-4gjm (Exploit, Vendor Advisory)
- github.com/FlintSH/Flare/commit/7763d7b954799552f287ab9260bb1353f8880163 (Patch)
- github.com/FlintSH/Flare/releases/tag/v1.7.1 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-26993?
- CVE-2026-26993 is a medium-severity vulnerability in Flintsh Flare, classified under Cross-site Scripting. CVSS score: 4.6/10. Published 2026-02-20.
- How severe is CVE-2026-26993?
- Medium severity. CVSS v3 base score is 4.6 out of 10.