CVEvulnerability
CVE-2026-48515
6.3 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-06-22
- Last modified
- 2026-06-25
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 6.3 MEDIUM — CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-770
Description
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's multi-dimensional array formatters read dimension lengths directly from the payload and allocate T[,], T[,,], or T[,,,] before validating that the dimension product matches the encoded element count. The formatter reads a guarded element array header, but allocation of the target multi-dimensional array happens before the dimensions are checked against that element count. A small payload can therefore declare large dimensions, provide an empty or tiny inner array, and cause a large heap allocation before element data is validated. This vulnerability is fixed in 2.5.301 and 3.1.7.
Affected configurations
• messagepack messagepack (< 2.5.301)
• messagepack messagepack (>= 3.0.3 < 3.1.7)
Related
Weakness · CWE (1)
- CWE-770 Allocation of Resources Without Limits or Throttling weakness
References
- https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-cxmj-83gh-fp49 Mitigation, Vendor Advisory