medium5.9
CVE-2026-107299
msgpack5 is a msgpack v5 implementation for node.js and the browser.
Impact
msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, the streaming decoder treats the reserved MessagePack byte 0xc1 as incomplete input instead of invalid input. When 0xc1 begins a stream, subsequent data remains buffered while the decoder waits for bytes that cannot make the value valid, allowing a remote peer to exhaust memory. This issue is fixed in version 6.1.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | msgpack5 | < 6.1.0 | 6.1.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-26wq-p25c-j6fv
- https://github.com/mcollina/msgpack5/security/advisories/GHSA-26wq-p25c-j6fv
- https://github.com/mcollina/msgpack5/commit/85da345bf1acc18ca441741e5cf4aa0ed0d69314
- https://github.com/mcollina/msgpack5/releases/tag/v6.1.0