How severe is CVE-2024-21634?

CVE-2024-21634 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2024-21634?

CVE-2024-21634 affects the following packages: com.amazon.ion:ion-java (Maven), software.amazon.ion:ion-java (Maven). Ecosystems affected: Maven.

How do I fix CVE-2024-21634?

Update com.amazon.ion:ion-java to 1.10.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-21634 is resolved across your whole dependency graph.

How do I detect CVE-2024-21634 in my Maven dependencies?

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

How do I mitigate CVE-2024-21634 if there is no patch (or I can't update yet)?

Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Is CVE-2024-21634 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-21634 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-2024-21634?

CVE-2024-21634 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 58th 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-2024-21634?

CVE-2024-21634 is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2024-21634 published, and has it been updated?

CVE-2024-21634 was published on January 3, 2024 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.

☕

☕ Maven

Not in CISA KEV

HIGH severity

CVE-2024-21634 — ion-java

HIGH

CVE-2024-21634 is a high-severity (CVSS 7.5) CWE-770 vulnerability in com.amazon.ion:ion-java. A fix is available for com.amazon.ion:ion-java — see the affected versions and patch details below.

Ion Java StackOverflow vulnerability

Also known asGHSA-264p-99wq-f4j6

Published

Jan 3, 2024

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

1 / 2

Exploits

None indexed

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

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 CVE-2024-21634.

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs58th percentile — riskier than 58% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

☕com.amazon.ion:ion-java☕software.amazon.ion:ion-java

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Impact

A potential denial-of-service issue exists in ion-java for applications that use ion-java to:

Deserialize Ion text encoded data, or
Deserialize Ion text or binary encoded data into the IonValue model and then invoke certain IonValue methods on that in-memory representation.

An actor could craft Ion data that, when loaded by the affected application and/or processed using the IonValue model, results in a StackOverflowError originating from the ion-java library.

Impacted versions: <1.10.5

Patches

The patch is included in ion-java >= 1.10.5.

Workarounds

Do not load data which originated from an untrusted source or that could have been tampered with. Only load data you trust.

If you have any questions or comments about this advisory, we ask that you contact AWS/Amazon Security via our vulnerability reporting page [1] or directly via email to [email protected]. Please do not create a public GitHub issue.

[1] https://aws.amazon.com/security/vulnerability-reporting

Affected Packages

2 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`com.amazon.ion:ion-java`	all versions	1.10.5`com.amazon.ion:ion-java:1.10.5`
☕Maven	`software.amazon.ion:ion-java`	all versions	No fix

Affected Products

1 product · 1 configurations

Application

ionamazon

< 1.10.5

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.amazon.ion:ion-java, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.amazon.ion:ion-java to 1.10.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-21634 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

IMPORTANT impact: Red Hat products that include the affected ion-java component can be subject to a remotely triggered denial of service. An unauthenticated attacker can provide maliciously crafted Ion text or binary data for deserialization into the IonValue model; processing the resulting structure can cause a…

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Source: Red Hat security advisory for CVE-2024-21634 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat JBoss Enterprise Application Platform 8	see advisory	RHSA-2024:7442
Red Hat JBoss Enterprise Application Platform 8.0 for RHEL 8	`eap8-amazon-ion-java-0:1.11.9-2.redhat_00001.1.el8eap`	RHSA-2024:7441

Frequently Asked Questions

### Impact A potential denial-of-service issue exists in `ion-java` for applications that use `ion-java` to: * Deserialize Ion text encoded data, or * Deserialize Ion text or binary encoded data into the `IonValue` model and then invoke certain `IonValue` methods on that in-memory representation. An actor could craft Ion data that, when loaded by the affected application and/or processed using the `IonValue` model, results in a `StackOverflowError` originating from the `ion-java` library. Impacted versions: <1.10.5 ### Patches The patch is included in `ion-java` >= 1.10.5. ### Workaroun