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CVE-2021-23758: Ajax.NET Professional Deserialization of Untrusted Data Vulnerability

Ajax.NET Professional Ajax.NET Professional · in CISA KEV since 2026-08-26

2026-08-26added to KEV
2026-09-09federal remediation due date
83.63%EPSS exploit probability (30 days) 99.7th percentile
9.8 CRITICALCVSS 3.1
Unknownknown ransomware use
1,727days from NVD publication to KEV

What it is

Ajax.NET Professional (AjaxPro) contains a deserialization of untrusted data vulnerability that could allow for remote code execution via arbitrary .NET classes. The impacted product(s) could be end-of-life (EoL) and/or end-of-service (EoS). Users are advised to discontinue use and/or transition to a supported version.

Required action (CISA)

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

CWECWE-502
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD published2021-12-03 (Analyzed)

Original records: NVD · CISA KEV · JSON: /api/cve/CVE-2021-23758.json · all KEV CVEs

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