CVE-2026-66273

High

Description

A pre-authentication attacker could leverage type size/count handling to cause excessive allocation leading to potential denial of service. This issue affects Apache Qpid Proton-J: through 0.34.1. Users are recommended to upgrade to version 0.35.0, which fixes the issue.

SeverityHigh

CVSS7.5

Exploit probability—

Product

Apache Qpid Proton-j

PublishedAug 5, 2026

First seenAug 5, 2026

Weakness typeCWE-789CWE-789

How to fix

Update

apache qpid_proton-j0.35.0 or later

Vendor advisories

lists.apache.org/thread/z34s9v5w05qk4qqtz5fs3v9wpxz6fnbh

Affected products

Product	Affected versions	Fixed in
apache qpid_proton-j	v < 0.35.0	0.35.0

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