CVE-2026-5426

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

Is your site exposed to CVE-2026-5426?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.5

HIGH

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

EPSS — Exploit Prediction

0.0007

Probability of exploitation

0.20%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-321 CWE-321

CWE-502 Deserialization of Untrusted Data

References

Other References

https://github.com/mandiant/Vulnerability-Disclosures/blob/master/2026/MNDT-2026-0009.md https://www.digital-knowledge.co.jp/product/kd/

Frequently Asked Questions

What is CVE-2026-5426? +

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 It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-5426? +

CVE-2026-5426 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0007, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-5426? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-11347

The linqi application contains hardcoded cryptographic keys. Additionally, the application uses a weak algorithm with a limited ASCII charset to …

CVE-2026-34022

The Wertheim SafeController Family 65000, Controller 65000 - AssemblyVersion 6.11.8130.22319, uses weak custom cryptographic algorithms with hard-coded cryptographic keys to …

CVE-2026-34029

The Wertheim SafeController Software, AssemblyVersion 6.15.8328.28014, contains a hard-coded cryptographic key in the SafeSystem.Infrastructure.Security.dll component. An attacker with access to …

CVE-2026-45433

This vulnerability exists in GX Earth 2022 ONT models due to the presence of hardcoded RSA private key within the …

CVE-2025-1099

This vulnerability exists in Tapo C500 Wi-Fi camera due to hard-coded RSA private key embedded within the device firmware. An …

CVE-2025-34500

Deck Mate 2's firmware update mechanism accepts packages without cryptographic signature verification, encrypts them with a single hard-coded AES key …