CVE-2026-44375 json
Nerdbank.MessagePack: Attacker-controlled stackalloc in DateTime decoding causes process-terminating StackOverflowException
published 2026-05-06 6 mo ago modified 2026-10-26 13 d ago also GHSA-2cwq-pwfr-wcw3 , EUVD-2026-30299
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 29%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- nuget Nerdbank.MessagePack 1.1.62
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.35% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | Nerdbank.MessagePack | <1.1.62 |
1.1.62 |
Affected products
- AArnott Nerdbank.MessagePack
Classification
- Weakness
-
- CWE-789 Memory Allocation with Excessive Size Value
References
-
github.com
/AArnott/Nerdbank.MessagePack/pull/941
web
-
github.com
/AArnott/Nerdbank.MessagePack/commit/7d1eb319cfabe7280e70699946c9a48579fa2f30
web
-
github.com
/AArnott/Nerdbank.MessagePack/security/advisories/GHSA-2cwq-pwfr-wcw3
web
-
github.com
/AArnott/Nerdbank.MessagePack/releases/tag/v1.1.62
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-44375
advisory
-
github.com
/AArnott/Nerdbank.MessagePack
package
-
github.com
/msgpack/msgpack/blob/master/spec.md#timestamp-extension-type
web
Sources
- CVE List CVE-2026-44375
- GitHub Advisory GHSA-2cwq-pwfr-wcw3
- NVD CVE-2026-44375
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