AArnott Nerdbank.MessagePack up to 1.1.61 memory allocation

Summaryinfo

A vulnerability marked as problematic has been reported in AArnott Nerdbank.MessagePack up to 1.1.61. This affects an unknown function. The manipulation leads to memory allocation. This vulnerability is traded as CVE-2026-44375. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in AArnott Nerdbank.MessagePack up to 1.1.61. This issue affects an unknown code. The manipulation with an unknown input leads to a memory allocation vulnerability. Using CWE to declare the problem leads to CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. Impacted is availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-44375 since 05/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 1.1.62 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 7d1eb319cfabe7280e70699946c9a48579fa2f30 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Banking Software

Vendor

• AArnott

Name

• Nerdbank.MessagePack

Version

• 1.1.0
• 1.1.1
• 1.1.2
• 1.1.3
• 1.1.4
• 1.1.5
• 1.1.6
• 1.1.7
• 1.1.8
• 1.1.9
• 1.1.10
• 1.1.11
• 1.1.12
• 1.1.13
• 1.1.14
• 1.1.15
• 1.1.16
• 1.1.17
• 1.1.18
• 1.1.19
• 1.1.20
• 1.1.21
• 1.1.22
• 1.1.23
• 1.1.24
• 1.1.25
• 1.1.26
• 1.1.27
• 1.1.28
• 1.1.29
• 1.1.30
• 1.1.31
• 1.1.32
• 1.1.33
• 1.1.34
• 1.1.35
• 1.1.36
• 1.1.37
• 1.1.38
• 1.1.39
• 1.1.40
• 1.1.41
• 1.1.42
• 1.1.43
• 1.1.44
• 1.1.45
• 1.1.46
• 1.1.47
• 1.1.48
• 1.1.49
• 1.1.50
• 1.1.51
• 1.1.52
• 1.1.53
• 1.1.54
• 1.1.55
• 1.1.56
• 1.1.57
• 1.1.58
• 1.1.59
• 1.1.60
• 1.1.61

License

• open-source

Website

• Product: https://github.com/AArnott/Nerdbank.MessagePack/

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