CVE-2026-106448
CVE-2026-106448 · StableLib: Prototype poisoning via `__proto__` map keys in CBOR decoding
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 8.9 · High · EPSS 0.4% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
stablelib
- Versions
- < 2.0.4: Affected
No fix published
@stablelib/cbor npm
- Affected ranges
- SEMVER: < 2.0.3
Update to 2.0.3