CVE-2026-104020

HIGH 7.5

Uncontrolled recursion in the Ion reader in Amazon Ion Python

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

Uncontrolled recursion in the Ion reader in Amazon Ion Python before 0.15.0 might allow a remote unauthenticated actor to crash the application using the library, resulting in a denial of service, via a crafted, deeply nested Ion value. To remediate this issue, users should upgrade to version 0.15.0 or later.

CWE	CWE-674
Vendor	amazon
Product	ion-python
Published	Oct 1, 2026
Last Updated	Oct 1, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

Amazon / ion-python

0 < 0.15.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/amazon-ion/ion-python/releases/tag/v0.15.0 aws.amazon.com: https://aws.amazon.com/security/security-bulletins/2026-122-aws/ github.com: https://github.com/amazon-ion/ion-python/security/advisories/GHSA-93q6-f8hx-vv7f

Credits

University of Manchester