CVE-2026-107300

msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, the streaming decoder recursively invokes itself for each complete MessagePack value remaining in a chunk. A remote peer can send one chunk containing many small valid values, causing recursion proportional to the value count, exhausting the JavaScript call stack, and interrupting the process or stream. This issue is fixed in version 6.1.0.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/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 36% of CVEs (scores of 2026-10-25)

CWE

CWE-674

Published

2026-10-08

Modified

2026-10-08

Record from

the NVD, synced 2026-10-19

Packages (OSV)

References

• https://github.com/mcollina/msgpack5/commit/77fbef144d05def5d16fc22c37caa64c0a7efeba
• https://github.com/mcollina/msgpack5/releases/tag/v6.1.0
• https://github.com/mcollina/msgpack5/security/advisories/GHSA-5x5g-h9x8-2fh9

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