XSS in Eclipse Foundation Open Vsx

CVE-2026-4983

Open VSX Registry does not sanitize SVG files uploaded as extension icons prior to storage, and serves them with Content-Type: image/svg+xml without security headers such as Content-Security-Policy or Content-Disposition: attachment. This…

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 4.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4983?
CVE-2026-4983 is a medium-severity vulnerability in Eclipse Foundation Open Vsx, classified under Cross-site Scripting. CVSS score: 4.1/10. Published 2026-06-23.
How severe is CVE-2026-4983?
Medium severity. CVSS v3 base score is 4.1 out of 10.