Summary
Amazon.IonDotnet is a library for the Dotnet language that is used to read and write Amazon Ion data. An issue exists where, under certain circumstances, the library could an infinite loop, resulting in denial of service. As of August 20, 2025, this library has been deprecated and will not receive further updates.
Impacted versions:
<1.3.2
Workarounds
Only accept data from trusted sources, written using a supported Ion library.
References
If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.
Impact
An infinite loop issue in Amazon.IonDotnet library versions <v1.3.2 may allow a threat actor to cause a denial of service through a specially crafted text input. This invalid input triggered an error condition in the parser that was handled improperly, resulting in an infinite loop.
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
This issue has been addressed in Amazon.IonDotnet version 1.3.2. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Frequently Asked Questions
- What is CVE-2025-11573? CVE-2025-11573 is a high-severity uncontrolled resource consumption vulnerability in Amazon.IonDotnet (nuget), affecting versions < 1.3.2. It is fixed in 1.3.2. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- Which versions of Amazon.IonDotnet are affected by CVE-2025-11573? Amazon.IonDotnet (nuget) versions < 1.3.2 is affected.
- Is there a fix for CVE-2025-11573? Yes. CVE-2025-11573 is fixed in 1.3.2. Upgrade to this version or later.
- Is CVE-2025-11573 exploitable, and should I be worried? Whether CVE-2025-11573 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-11573 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-11573? Upgrade
Amazon.IonDotnetto 1.3.2 or later.