Vulnerability · Published Aug 18, 2026 · Assigned by AMZN

CVE-2026-75936Memory-amplification denial of service via GZIP decompression bomb in Amazon ion-java

High 7.5

In plain English

A high-severity security flaw in Amazon Ion Java from Amazon Ion. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.6%top 50.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Improper handling of highly compressed data in the GZIP auto-decompression handler in Amazon ion-java before 1.12.0 might allow remote actors to cause a denial of service via a crafted compressed Ion document that expands to an arbitrarily large size upon decompression. To remediate this issue, users should upgrade to version 1.12.0 and configure withGzipDecompressionEnabled(false) and/or set an explicit withMaximumBufferSize() when parsing untrusted input.

Affected products (as reported)

Vendor	Product	Versions
Amazon Ion	Amazon Ion Java	0 – before 1.12.0

Weakness: CWE-409 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/amazon-ion/ion-java/releases/tag/v1.12.0 patch
https://github.com/amazon-ion/ion-java/security/advisories/GHSA-wj53-jv76-65mc third-party-advisory
https://aws.amazon.com/security/security-bulletins/2026-083-aws/ vendor-advisory