CVE-2026-44375
Nerdbank.MessagePack: Attacker-controlled stackalloc in DateTime decoding causes process-terminating StackOverflowException
- State
- Published
- Severity
- 7.5 High
- Published
- May 14, 2026
- Updated
- May 14, 2026
- Reserved
- May 5, 2026
Description
Nerdbank.MessagePack is a NativeAOT-compatible MessagePack serialization library. Prior to 1.1.62, Nerdbank.MessagePack contains an uncontrolled stack allocation vulnerability in DateTime decoding. A malicious MessagePack payload can declare an oversized timestamp extension length, causing the reader to allocate an attacker-controlled number of bytes on the stack. This can trigger a StackOverflowException, which is not catchable by user code and terminates the process. This vulnerability is fixed in 1.1.62.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
Weaknesses
- CWE-789 Memory Allocation with Excessive Size Value
Affected Products
| Product | Versions |
|---|---|
Nerdbank.MessagePackAArnott |
|
References
- https://github.com/AArnott/Nerdbank.MessagePack/security/advisories/GHSA-2cwq-pwfr-wcw3
- https://github.com/AArnott/Nerdbank.MessagePack/pull/941
- https://github.com/AArnott/Nerdbank.MessagePack/commit/7d1eb319cfabe7280e70699946c9a48579fa2f30
- https://github.com/AArnott/Nerdbank.MessagePack/releases/tag/v1.1.62
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