CVE-2026-4983

MEDIUM EPSS 13.2%
Published Jun 23, 20261w ago · Modified Jun 23, 20261w ago
4.1 CVSS 3.1
Medium
Find Similar
Published Jun 23, 2026 1w ago
Last Modified Jun 23, 2026 1w ago

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.

CVSS Details

Base Score
4.1
Exploitability
2.3
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction Required
Scope Changed
Confidentiality None
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
13.2% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

References 1

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.