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Vulnerability record · CVE-2020-5234 · published 31 January 2020

CVE-2020-5234: Messagepack stack-based buffer overflow vulnerability

Messagepack · Messagepack

MessagePack for C# and Unity before version 1.9.11 and 2.1.90 has a vulnerability where untrusted data can lead to DoS attack due to hash collisions and stack overflow. Review the linked GitHub Security Advisory for more information and remediation steps.

6.5 CVSS 3.1 Medium EPSS 1.6% · top 25.5% CWE-121 · Stack-based buffer overflowCWE-787 · Out-of-bounds write
6.5CVSS 3.1 base score, v2 6.8
1.6%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
8References
17 Jun 2026Last modified by NVD

Description

MessagePack for C# and Unity before version 1.9.11 and 2.1.90 has a vulnerability where untrusted data can lead to DoS attack due to hash collisions and stack overflow. Review the linked GitHub Security Advisory for more information and remediation steps.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/neuecc/MessagePack-CSharp/commit/56fa86219d01d0a183babbbbcb34abbdea588a02 PatchThird Party Advisory
https://github.com/neuecc/MessagePack-CSharp/commit/f88684078698386df02204f13faeff098a61f007
https://github.com/neuecc/MessagePack-CSharp/issues/810
https://github.com/neuecc/MessagePack-CSharp/security/advisories/GHSA-7q36-4xx7-xcxf Third Party Advisory
https://github.com/neuecc/MessagePack-CSharp/commit/56fa86219d01d0a183babbbbcb34abbdea588a02 PatchThird Party Advisory
https://github.com/neuecc/MessagePack-CSharp/commit/f88684078698386df02204f13faeff098a61f007
https://github.com/neuecc/MessagePack-CSharp/issues/810
https://github.com/neuecc/MessagePack-CSharp/security/advisories/GHSA-7q36-4xx7-xcxf Third Party Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2020-5234), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.