msgpack5: Many buffered values can exhaust the streaming decoder stack
Impact
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.
Patches
The streaming decoder now drains concatenated values iteratively with constant call-stack depth.
Workarounds
Limit the number of MessagePack values accepted in one chunk, or split large batches before passing them to the decoder stream.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | msgpack5 | < 6.1.0 | 6.1.0 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-674- Platform
- npm
- Package
msgpack5- Disclosed
- 08.10.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-5x5g-h9x8-2fh9 - CC BY 4.0
Vulnerability history: msgpack5
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 8
- First → latest
- 03.2021 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 2
- Medium 5
- Low 1
Disclosures per year
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 0
- 2026: 7
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msgpack5: Many buffered values can exhaust the streaming decoder stack this entry
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