by Kastro
Paper/Archive/CVE-2026-5426

CVE-2026-5426

Digital Knowledge KnowledgeDeliver — KnowledgeDeliver deployments before February 24, 2026 use a static ASP.NET/IIS machineKey value

EPSS 1%CVSS 9.1
critical.is priorityof 100
40
CVSS 9.1 (ADP)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 63.1.631 × 2012.6No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

Affected

ProductAffectedFixed inSource
KnowledgeDeliver< 2026022420260224CNA

Scores by source

CISA ADP9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

writeupgithub.com/mandiant/Vulnerability-Disclosures/blob/master/2026/MNDT-2026-0009.mdrefdigital-knowledge.co.jp/product/kdwriteupcloud.google.com/blog/topics/threat-intelligence/knowledgedeliver-viewstate-deserialization-vulnerability