CVE-2026-4983

Published Jun 23, 2026

Last updated 6 days ago

Overview

Description
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 allows an attacker to publish an extension with a malicious SVG icon and achieve stored cross-site scripting (XSS) when a user navigates directly to the icon URL. On deployments using local storage, script execution occurs within the Open VSX application origin, enabling session hijacking, authentication token theft, and unauthorized extension publishing. On deployments backed by external storage (such as open-vsx.org with an S3-backed CDN), execution is confined to the storage origin, reducing impact but still permitting phishing attacks and credential harvesting through attacker-crafted pages.
Source
emo@eclipse.org
NVD status
Analyzed
Products
open_vsx

Risk scores

CVSS 3.1

Type
Primary
Base score
5.4
Impact score
2.7
Exploitability score
2.3
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Severity
MEDIUM

Weaknesses

emo@eclipse.org
CWE-79

Social media

Hype score
Not currently trending

Configurations

References

Sources include official advisories and independent security research.