CVE-2026-75935

Memory-amplification denial of service via declared-length preallocation in Amazon ion-java

State: Published
Severity: 8.7 High
Published: Aug 18, 2026
Updated: Aug 19, 2026
Reserved: Aug 18, 2026

Description

Uncontrolled memory allocation in the binary Ion stream cursor in Amazon ion-java before 1.12.0 might allow remote actors to cause a denial of service via a crafted Ion binary document containing a declared-length field that causes excessive heap preallocation.

To remediate this issue, users should upgrade to version 1.12.0.

Scores

CVSS	Score	Vector	Source
4.0	8.7 High	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	AMZN
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	AMZN

Weaknesses

CWE-789 Memory allocation with excessive size value

Affected Products

Product	Versions
Amazon Ion JavaAmazon Ion	1.9.0 to before 1.12.0Affected

References

https://github.com/amazon-ion/ion-java/releases/tag/v1.12.0patch
https://aws.amazon.com/security/security-bulletins/2026-083-aws/vendor-advisory
https://github.com/amazon-ion/ion-java/security/advisories/GHSA-822f-6gg9-whr5third-party-advisory

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