Improper Data Handling in Amazon ion-java Affects Remote Users
CVE-2026-85786

8.7HIGH

Key Information:

Vendor

Amazon

Status
Ion-java
Vendor
CVE Published:
4 September 2026

What is CVE-2026-85786?

A vulnerability exists in Amazon ion-java prior to version 1.12.1 that improperly handles highly compressed data. This flaw could allow remote attackers to exploit the handling of crafted compressed Ion documents, potentially triggering a denial of service due to an arbitrary size expansion during decompression. The issue arises from inadequate implementation of the GZIP auto-decompression opt-out that was previously introduced for another vulnerability. Users are advised to upgrade to version 1.12.1 to ensure protection against this issue.

Affected Version(s)

ion-java 0 < 1.12.1

References

https://github.com/amazon-ion/ion-java/releases/tag/v1.12.1
patchrelease-notes
https://aws.amazon.com/security/security-bulletins/2026-1...
vendor-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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