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.
CVE-2020-5234
This medium-severity CVE scores 4.8 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 32% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 4.8
- EG Score
- 4.8(medium)
- EPSS
- 72.6%
- KEV
- Not listed
Published
January 31, 2020
Last Modified
November 21, 2024
References (8)
- security-advisories@githubhttps://github.com/neuecc/MessagePack-CSharp/commit/56fa86219d01d0a183babbbbcb34abbdea588a02
- security-advisories@githubhttps://github.com/neuecc/MessagePack-CSharp/commit/f88684078698386df02204f13faeff098a61f007
- security-advisories@githubhttps://github.com/neuecc/MessagePack-CSharp/issues/810
- security-advisories@githubhttps://github.com/neuecc/MessagePack-CSharp/security/advisories/GHSA-7q36-4xx7-xcxf
- af854a3a-2127-422b-91ae-364da2661108https://github.com/neuecc/MessagePack-CSharp/commit/56fa86219d01d0a183babbbbcb34abbdea588a02
- af854a3a-2127-422b-91ae-364da2661108https://github.com/neuecc/MessagePack-CSharp/commit/f88684078698386df02204f13faeff098a61f007
- af854a3a-2127-422b-91ae-364da2661108https://github.com/neuecc/MessagePack-CSharp/issues/810
- af854a3a-2127-422b-91ae-364da2661108https://github.com/neuecc/MessagePack-CSharp/security/advisories/GHSA-7q36-4xx7-xcxf
Affected Packages
(5 across 1 ecosystem)
NuGet(5)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| MessagePack | 2.0.107-alpha ... 2.1.80 (15 versions) | 2.1.90 | — |
| MessagePack.ImmutableCollection | 2.0.107-alpha ... 2.1.80 (15 versions) | 2.1.90 | — |
| MessagePack.ReactiveProperty | 2.0.107-alpha ... 2.1.80 (15 versions) | 2.1.90 | — |
| MessagePack.Unity | — | 2.1.90 | — |
| MessagePack.UnityShims | 2.0.107-alpha ... 2.1.80 (15 versions) | 2.1.90 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 44× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-11 08:25 UTCEPSS rescore
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- 2026-07-02 16:57 UTCEPSS rescore
- 2026-07-02 11:12 UTCOSV refresh
- 2026-07-01 15:03 UTCEPSS rescore
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- 2026-06-25 13:48 UTCEPSS rescore
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- 2026-06-24 14:03 UTCEPSS rescore
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- 2026-06-14 09:43 UTCOSV refresh
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- 2026-05-31 00:15 UTCEPSS rescore
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- 2026-05-29 13:42 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
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- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-27 08:22 UTCEG score recompute
- 2026-05-26 13:42 UTCEPSS rescore
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- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-25 21:46 UTCOSV refresh
Related CVEs(same CWE)
Same CWE
10 shownCWE-121 · CWE-787
Frequently asked(5)
What is CVE-2020-5234?
When was CVE-2020-5234 disclosed?
Is CVE-2020-5234 actively exploited?
What is the CVSS score of CVE-2020-5234?
How do I remediate CVE-2020-5234?
Dependency Blast Radius
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