CVE-2026-106448: Stablelib

High severity, CVSS 8.9. EPSS: 0.4% chance of exploitation in the next 30 days.

StableLib is a stable library of useful TypeScript and JavaScript code. Prior to 2.0.4, the @stablelib/cbor CBOR map decoding path creates ordinary JavaScript objects and assigns attacker-controlled keys with bracket assignment. A map key named __proto__ invokes the inherited prototype setter instead of creating an ordinary own property, allowing the decoded object's prototype to contain attacker-controlled authorization or feature-flag values. Downstream code that trusts normal property lookup or merges the decoded object can therefore make security-sensitive decisions using inherited attacker data. This issue is fixed in version 2.0.4.

Affected products

• Stablelib Stablelib: before 2.0.4 (fixed in 2.0.4)

Published 2026-10-06. Last modified 2026-10-07.