CVE record
CVE-2021-23758
Ajax.NET Professional Deserialization of Untrusted Data Vulnerability
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.
CVE evidence
Known exploitation
Listed in CISA KEV
Absence from the fetched catalog does not establish that exploitation has not occurred.
Severity
critical
CVSS 9.8 · CVSS_V3
Affected packages
0
Supported package records returned by OSV. Vendor and product names are not used to infer matches.
CISA Known Exploited Vulnerabilities
Catalog record
- Vendor / project
- Ajax.NET Professional
- Product
- Ajax.NET Professional
- Date added
- Aug 26, 2026
- CISA federal remediation due date
- Sep 9, 2026
- Required action
- 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.
- Known ransomware campaign use
- Unknown
- CWE
- CWE-502
OSV package mapping
Affected open-source packages
OSV did not return a package mapping in the five supported ecosystems. RequestGuard does not infer package names from the CISA vendor or product fields.