GHSA-8v6j-gc74-fmpp is a medium-severity (CVSS 6.3) Cross-site Scripting (XSS) vulnerability in AjaxNetProfessional. A fix is available for AjaxNetProfessional — see the affected versions and patch details below.
Ajax Pro Cross-site Scripting
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-8v6j-gc74-fmpp.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-8v6j-gc74-fmpp plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
AjaxNetProfessionalReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
Overview
Affected versions of this package are vulnerable to Deserialization of Untrusted Data due to the possibility of deserialization of arbitrary JavaScript objects.
Description
Cross-Site Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into otherwise benign and trusted websites. XSS attacks occur when an attacker uses a web application to send malicious code, generally in the form of a browser side script, to a different end user. Flaws that allow these attacks to succeed are quite widespread and occur anywhere a web application uses input from a user within the output it generates without validating or encoding it.
XSS effects vary in range from petty nuisance to significant security risk, depending on the sensitivity of the data handled by the vulnerable site and the nature of any security mitigation implemented by the site's owner network.
Releases
Releases before version 21.12.22.1 are affected. Please be careful to download any binary DLL from other web sites, especially we found NuGet packages not owned by us that contain vulnerable versions.
Workarounds
A workaround exists that replaces one of the core JavaScript files embedded in the library. Using a XML configuration allows to replace the default JavaScript code to be replaced with the version on GitHub.
<configuration>
<configSections>
<sectionGroup name="ajaxNet">
<section name="ajaxSettings" type="AjaxPro.AjaxSettingsSectionHandler,AjaxPro.2" requirePermission="false" restartOnExternalChanges="true"/>
</sectionGroup>
</configSections>
<ajaxNet>
<ajaxSettings>
<coreScript>~/ajaxpro-core-fixed.js</coreScript>
</ajaxSettings>
</ajaxNet>
</configuration>
Copy the file core.js from the main project folder to your web server root folder and rename that ajaxpro-core-fixed.js.
Clients need to refresh the web page to download the changed JavaScript code.
References
Commit fixing the issue: c89e39b9679fcb8ab6644fe21cc7e652cb615e2b
Note: the official Ajax.NET Professional (AjaxPro) NuGet package is available here: https://www.nuget.org/packages/AjaxNetProfessional/
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | AjaxNetProfessional | all versions | 21.12.22.1dotnet add package AjaxNetProfessional --version 21.12.22.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for AjaxNetProfessional, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update AjaxNetProfessional to 21.12.22.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8v6j-gc74-fmpp is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-8v6j-gc74-fmpp can be triaged on real exposure rather than presence alone.
Tailored to GHSA-8v6j-gc74-fmpp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-8v6j-gc74-fmpp in your dependencies?
O3 Security finds GHSA-8v6j-gc74-fmpp across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.