CVE-2026-66276 Apache Qpid Proton-J: Unbounded disposition range handling can lead to denial of service

Medium 6.5 Published Updated

An authenticated attacker can cause denial of service in Apache Qpid Proton-J by sending crafted disposition frames with large ranges.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-66276?

CVE-2026-66276 is a medium-severity denial of service vulnerability in Apache Qpid Proton-J, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

An authenticated attacker can craft a disposition frame with large or illegal ranges causing excessive CPU usage due to naive range handling, leading to 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.

Weakness: CWE-606

Which versions are affected by CVE-2026-66276?

It affects 1 product.

Products include Apache Qpid Proton-J.

How do I fix CVE-2026-66276?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-66276 being exploited?

There is no known exploitation of CVE-2026-66276 in the wild and no public exploit code.

Sources

Also known as CLEANSTART-2026-JV92221, GHSA-jx9q-477g-4wgw.

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