Ajax.NET Professional Deserialization of Untrusted Data Vulnerability

Ajax.NET Professional Ajax.NET Professional

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. Added to CISA KEV on 2026-08-26 (federal deadline 2026-09-09).

First seen: 26 Aug 2026
Last update: 26 Aug 2026, 12:00 UTC
Identifiers: CVE-2021-23758
Source: CISA KEV

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Ajax.NET Professional Deserialization of Untrusted Data Vulnerability
Severity: high, exploited in the wild. Patch status: patched.
Affected: Ajax.NET Professional Ajax.NET Professional
Ids: CVE-2021-23758

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. Added to CISA KEV on 2026-08-26 (federal deadline 2026-09-09).

## Steps
1. Search the repo, its CI and infra config for Ajax.NET Professional Ajax.NET Professional. If present, report the version in use and whether it's affected.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2021-23758") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://nvd.nist.gov/vuln/detail/CVE-2021-23758
https://pwned.coffee/i/ajax-net-professional-deserialization-of-untrusted-data-cve-2021-23758

Sources

NVD: CVE-2021-23758

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