CVE-2026-75935 and CVE-2026-75936 - Issue with Amazon ion-java - Memory-amplification denial of service

unknownCVE-2026-75935 CVE-2026-75936

Bulletin ID: 2026-083-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 08/18/2026 12:30 PM PDT Description: ion-java is a Java library that implements the Amazon Ion data format specification. We identified CVE-2026-75935, memory-amplification denial of service via declared-length preallocation, and CVE-2026-75936, memory-amplification denial of service via highly compressed data expansion. Affected versions: < 1.12.0 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.

CSIRTS triage

vendor: Amazon product: ion-java Denial of serviceaffected: < 1.12.0

What: ion-java library contains two memory-amplification denial of service vulnerabilities through declared-length preallocation and highly compressed data expansion.
Who is affected: Applications using Amazon ion-java versions prior to 1.12.0.
Urgency: Important; denial of service vulnerability affecting Java applications using the Amazon Ion library.
Action: Upgrade ion-java to version 1.12.0 or later.

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Details

Source: AWS Security Bulletins (INTL · vendor-psirt · site)
Severity: unknown
Published: 2026-08-20
Exploitation: Not in CISA KEV at last sync

Original advisory: https://aws.amazon.com/security/security-bulletins/rss/2026-083-aws/

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-759350.44% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 37% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-759360.44% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 37% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-75935	coverage & exploitation status	NVD · CVE.org
CVE-2026-75936	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.