What is the CVSS score of CVE-2026-26335?

CVE-2026-26335 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of IIS are affected by CVE-2026-26335?

Calero VeraSMART installations are vulnerable to critical cryptographic key compromise due to hardcoded static encryption keys in configuration files.

Is there a public PoC exploit available for CVE-2026-26335?

Yes, a public proof-of-concept exploit is available for CVE-2026-26335. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-26335?

Within 24 hours: Identify and inventory all VeraSMART deployments and versions in your environment; isolate affected systems from untrusted networks if possible. Within 7 days: Implement network segmentation to restrict access to VeraSMART web applications; enable detailed logging and monitoring for suspicious authentication and data access patterns; begin testing upgrade path to VeraSMART 2022 R1 or later in a non-production environment. Within 30 days: Complete upgrade of all VeraSMART instances to version 2022 R1 or later; rotate all credentials and session tokens associated with affected systems; conduct forensic analysis for signs of exploitation.

IIS CVE-2026-26335

CRITICAL

Use of Hard-coded Cryptographic Key (CWE-321)

2026-02-13 disclosure@vulncheck.com

IIS .NET RCE Deserialization Verasmart

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:02 vuln.today

CVE Published

Feb 13, 2026 - 21:16 nvd

CRITICAL 9.8

DescriptionCVE.org

Calero VeraSMART versions prior to 2022 R1 use static ASP.NET/IIS machineKey values configured for the VeraSMART web application and stored in C:\\Program Files (x86)\\Veramark\\VeraSMART\\WebRoot\\web.config. An attacker who obtains these keys can craft a valid ASP.NET ViewState payload that passes integrity validation and is accepted by the application, resulting in server-side deserialization and remote code execution in the context of the IIS application.