CVE-2026-5426 | KnowledgeDeliver deployments before February 24, 2026 use a static ASP.NET/IIS machineKey value

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

Published: 2026-04-16 Last update: 2026-05-26 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-5426 is rated Moderate Risk (44.8/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.08%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-5426

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-17 0.08%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-5426

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 5.2 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-5426

GitHub Security Advisory for CVE-2026-5426

GHSA-g88c-8gfj-6c98 · Severity: high — Hard-coded ASP.NET/IIS machineKey value in Digital Knowledge KnowledgeDeliver deployments prior...

Affected software / configurations for CVE-2026-5426

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-5426

cvelogic Threat Intelligence