Vulnerability details
CVE-2026-107302
mcollina msgpack5
msgpack5: Truncated map32 headers throw an unexpected error
CVSS 3.1
7.5High
Official description
msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, the decoder reads the four-byte length of a map32 value before validating that the complete five-byte header is available. A truncated map32 header therefore causes a checked out-of-bounds buffer read and throws RangeError instead of IncompleteBufferError, which can unexpectedly terminate a request, stream, or worker in applications that wait for additional bytes after IncompleteBufferError. There is no adjacent-memory disclosure because the buffer implementation checks bounds. This issue is fixed in version 6.1.0.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.5High | 3.1 | CVEProject cvelistV5 (CNA) (GitHub_M) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| mcollina | msgpack5 | >= 4.1.0. < 6.1.0 | CVEProject cvelistV5 (CNA) |
References and advisories
3- https://github.com/mcollina/msgpack5/security/advisories/GHSA-8f34-f56x-9xph x_refsource_CONFIRM
- https://github.com/mcollina/msgpack5/commit/15443a1f2aa682a6aa37f1705ac628de5b866ad1 x_refsource_MISC
- https://github.com/mcollina/msgpack5/releases/tag/v6.1.0 x_refsource_MISC
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Details
- Published
- 2026-10-08
- Last updated
- 2026-10-19
- State
- Published
- Assigner (CNA)
- GitHub_M
Exploit prediction (EPSS)
0.52%
Probability of exploitation in 30 days
44.4%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-125Out-of-bounds Read