CVE-2026-107300: msgpack5: Many buffered values can exhaust the streaming decoder stack

October 8, 2026

The streaming decoder recursively invokes itself for every complete value remaining in a chunk. A single chunk containing many small valid MessagePack values can exhaust the JavaScript call stack and interrupt the process or stream.

References

github.com/advisories/GHSA-5x5g-h9x8-2fh9
github.com/mcollina/msgpack5/commit/77fbef144d05def5d16fc22c37caa64c0a7efeba
github.com/mcollina/msgpack5/releases/tag/v6.1.0
github.com/mcollina/msgpack5/security/advisories/GHSA-5x5g-h9x8-2fh9
nvd.nist.gov/vuln/detail/CVE-2026-107300

Code Behaviors & Features

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