### 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.
### 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.
### Impacted versions:
<1.3.2
### Patches
This issue has been addressed in Amazon.IonDotnet version [1.3.2](https://www.nuget.org/packages/Amazon.IonDotnet/1.3.2). We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
### 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](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [[email protected]](mailto:[email protected]). Please do not create a public GitHub issue.
- Source published
- 9 Oct 2025 22:15:57 UTC
- Source modified
- 9 Oct 2025 22:42:35 UTC
- Observed here
- 23 Oct 2026 16:01:25 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Publisher rating · HIGH