CVE-2026-107297
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.
- CVSS 3.1
- 5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 32% of CVEs (scores of 2026-10-26)
- CWE
- CWE-407
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-gcx5-hxj7-gpqq | npm | msgpack5 | <6.1.0 | 6.1.0 |