CVE-2026-107300: high-severity vulnerability in mcollina msgpack5
msgpack5: Many buffered values can exhaust the streaming decoder stack
Published
18Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5
exploitation probability
—
observed exploitation
nono source reports it
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/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
mcollina · msgpack5Related CVEs — mcollina msgpack5
In the same product, most dangerous first.
CVE-2021-21368MEDIUMPrototype poisoningEPSS 1.6%CVE-2026-107302HIGHmsgpack5: Truncated map32 headers throw an unexpected errorEPSS —CVE-2026-107301MEDIUMmsgpack5: Partial options disable prototype protectionEPSS —CVE-2026-107299MEDIUMmsgpack5: Reserved byte can cause unbounded stream bufferingEPSS —CVE-2026-107298MEDIUMmsgpack5: Deeply nested input can exhaust the decoder stackEPSS —CVE-2026-107297MEDIUMmsgpack5: Quadratic parsing in the streaming decoderEPSS —