CVE-2026-48515
MEDIUM
6.3
CVSS 4.0
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.
Metadata
Severity & Metrics
6.3
MEDIUM CVSS 4.0
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
Affected products (1)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| MessagePack-CSharp | MessagePack-CSharp | — | >= 3.1.7, < 3.1.7, < 2.5.301 |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| CWE-770 | cna | CWE-770: Allocation of Resources Without Limits or Throttling |
CVSS scores (1)
| Score | Severity | Version | Source | Vector |
|---|---|---|---|---|
| 6.3 | MEDIUM | 4.0 | cna | 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 |
References (1)
- https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-cxmj-83gh-fp49 https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-cxmj-83gh-fp49