CVE-2021-3918: Debian Linux

Critical severity, CVSS 9.8. EPSS: 3.8% chance of exploitation in the next 30 days.

json-schema is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Affected products

• Debian Debian Linux: version 10.0 only
• JSON-Schema Project JSON-Schema: before 0.4.0 (fixed in 0.4.0)

Published 2021-11-13. Last modified 2026-06-17.