CVE-2026-104020

high

Description

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.

References

https://github.com/amazon-ion/ion-python/security/advisories/GHSA-93q6-f8hx-vv7f

https://github.com/amazon-ion/ion-python/releases/tag/v0.15.0

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-91059

https://aws.amazon.com/security/security-bulletins/2026-122-aws/

Details

Source: Mitre, NVD

Published: 2026-10-01

Updated: 2026-10-02

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

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

Severity: High

CVSS v4

Base Score: 8.7

Vector: 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

Severity: High

EPSS

EPSS: 0.00441