CVE-2026-107300: CWE-674: Uncontrolled Recursion in mcollina msgpack5
Description
### 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.
CVSS v3.1
Score 7.5high
Affected software
mcollina
msgpack5
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The msgpack5 library for Node.js and browsers, before version 6.1.0, has a vulnerability where its streaming decoder recursively invokes itself for each complete MessagePack value in a chunk. A remote attacker can exploit this by sending a chunk with many small valid values, causing recursion proportional to the number of values. This uncontrolled recursion leads to exhaustion of the JavaScript call stack, resulting in denial of service by interrupting the process or stream. The vulnerability is identified as CWE-674 (Uncontrolled Recursion) and has a CVSS 3.1 score of 7.5 (high severity). The issue is fixed in msgpack5 version 6.1.0.
Potential Impact
An attacker can cause a denial of service by sending specially crafted MessagePack data that triggers deep recursion in the streaming decoder, exhausting the JavaScript call stack and interrupting the affected process or stream. There is no impact on confidentiality or integrity reported.
Mitigation Recommendations
Upgrade msgpack5 to version 6.1.0 or later, where this uncontrolled recursion vulnerability has been fixed. No other mitigations are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-10-07T15:53:23.587Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ac7d1292cdf04f6562ba9b2
Added to database: 10/08/2026, 17:21:45 UTC
Last enriched: 10/08/2026, 17:33:20 UTC
Last updated: 10/08/2026, 21:48:49 UTC
Views: 7
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