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Vulnerability record · CVE-2026-5426 · published 16 April 2026

CVE-2026-5426: Deserialization of untrusted data vulnerability

Hard-coded ASP.NET/IIS machineKey value in Digital Knowledge KnowledgeDeliver deployments prior to February 24, 2026 allows adversaries to circumvent ViewState validation mechanisms and achieve remote code execution via malicious ViewState deserialization attacks

9.1 CVSS 3.1 Critical EPSS 0.81% · top 44.8% CWE-321 · CWE-321CWE-502 · Deserialization of untrusted data Awaiting Analysis
9.1CVSS 3.1 base score
0.81%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
3References
17 Jun 2026Last modified by NVD

Description

Hard-coded ASP.NET/IIS machineKey value in Digital Knowledge KnowledgeDeliver deployments prior to February 24, 2026 allows adversaries to circumvent ViewState validation mechanisms and achieve remote code execution via malicious ViewState deserialization attacks

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

References

LinkTags
https://cloud.google.com/blog/topics/threat-intelligence/knowledgedeliver-viewstate-deserialization-vulnerability
https://github.com/mandiant/Vulnerability-Disclosures/blob/master/2026/MNDT-2026-0009.md
https://www.digital-knowledge.co.jp/product/kd/

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Source: NIST National Vulnerability Database (record CVE-2026-5426), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.