Allocation of Resources Without Limits or Throttling Affecting messagepack package, versions [,2.5.301)[3.0,3.1.7)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published28 Jun 2026
- disclosed25 Jun 2026
- creditAArnott
Introduced: 25 Jun 2026
NewCVE-2026-48515 (opens in a new tab)How to fix?
Upgrade MessagePack to version 2.5.301, 3.1.7 or higher.
Overview
MessagePack is a MessagePack(MsgPack) Serializer for C#(.NET, .NET Core, Unity, Xamarin).
Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling in the deserialization process for multi-dimensional arrays. An attacker can cause excessive memory allocation by supplying crafted payloads with large dimension values and a small element array, leading to out-of-memory exceptions, application termination, or high CPU usage from zero-initialization of oversized arrays. This is only exploitable if untrusted data is deserialized into models containing multi-dimensional arrays.
Workaround
This vulnerability can be mitigated by avoiding deserialization of untrusted payloads into schemas with multi-dimensional arrays and preferring bounded lists, dictionaries with count limits, or jagged arrays with application-level limits.