CVE-2026-5426
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedHard-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
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceDigital Knowledge KnowledgeDeliver deployments contain a hard-coded ASP.NET/IIS machineKey value that allows adversaries to forge ViewState tokens. Since ViewState validation relies on this key, attackers can craft malicious serialized payloads to achieve remote code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Locate KnowledgeDeliver installation directorySearch for folders named 'KnowledgeDeliver', 'KD', or check common IIS web root paths (C:\Inetpub\wwwroot\, /var/www/, /opt/) for KnowledgeDeliver application filesAffected if KnowledgeDeliver is not installed on the system
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Find web.config or machine.config filesSearch the KnowledgeDeliver installation directory for web.config, machine.config, or app.config files, typically found in the root or bin foldersAffected if No configuration files exist in the application directory
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Locate machineKey element in configurationOpen the found configuration files and search for the <machineKey> element within <system.web> sectionAffected if No machineKey element is present in the configuration
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Examine machineKey value for hard-coded contentInspect the validationKey and decryptionKey attributes within the <machineKey> element. Check if the values are static (long alphanumeric strings) rather than dynamically generated or set to 'AutoGenerate'Affected if The machineKey contains static validationKey or decryptionKey values instead of 'AutoGenerate' or environment-specific dynamically generated keys
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Verify key uniqueness across deploymentsCompare the machineKey values from this installation against known hard-coded default key values, or check if multiple environments share identical keysAffected if The machineKey value matches known hard-coded defaults or is identical to keys used in other environments
The environment is affected if KnowledgeDeliver is installed and the machineKey element in its configuration files contains static, hard-coded validationKey or decryptionKey values rather than dynamically generated or unique per-environment keys.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataReplace the hard-coded machineKey with a unique, cryptographically strong value generated for each environment, update all relevant configuration files, and invalidate existing sessions/tokens that may have been compromised.
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-5426 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-5426 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data