How severe is CVE-2025-11573?

No CVSS score has been assigned to CVE-2025-11573 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-11573?

CVE-2025-11573 affects the following packages: Amazon.IonDotnet (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2025-11573?

Update Amazon.IonDotnet to 1.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-11573 is resolved across your whole dependency graph.

How do I detect CVE-2025-11573 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Amazon.IonDotnet, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-11573 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2025-11573 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-11573 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-11573?

CVE-2025-11573 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 38th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-11573?

CVE-2025-11573 is classified as CWE-1286 (CWE-1286). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-11573 published, and has it been updated?

CVE-2025-11573 was published on October 9, 2025 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET NuGet

Not in CISA KEV

CVE-2025-11573 — Amazon.IonDotnet

Fix: amazon-ion/ion-dotnet#160

CVE-2025-11573 is a CWE-1286 vulnerability in Amazon.IonDotnet. A fix is available for Amazon.IonDotnet — see the affected versions and patch details below.

Denial of Service issue in Amazon.IonDotnet

Also known asGHSA-q5r6-9qwq-g2wj

Published

Oct 9, 2025

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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 CVE-2025-11573.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs38th percentile — riskier than 38% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

.NETAmazon.IonDotnet

Real-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

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. 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 or directly via email to [email protected]. Please do not create a public GitHub issue.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Amazon.IonDotnet`	all versions	1.3.2`dotnet add package Amazon.IonDotnet --version 1.3.2`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Amazon.IonDotnet, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Amazon.IonDotnet to 1.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-11573 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### 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, resulti

O3 Security · Impact-Aware SCA

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