medium5.9
CVE-2026-107297
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 reparses an incomplete array or map from the beginning whenever another chunk arrives. A remote peer can split one valid MessagePack container across many small chunks, causing completed elements to be decoded repeatedly, producing quadratic CPU use and blocking the event loop. 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-gcx5-hxj7-gpqq
- https://github.com/mcollina/msgpack5/security/advisories/GHSA-gcx5-hxj7-gpqq
- https://github.com/mcollina/msgpack5/commit/e4827641d3105e295cbbd56e9c5389978547eab4
- https://github.com/mcollina/msgpack5/releases/tag/v6.1.0