CVE-2026-66274Network attack vectorHinoki check available

Pre-authentication crash via unbounded type nesting

Published Aug 5, 2026 · Updated Aug 5, 2026

Uncontrolled recursion in Apache Qpid Proton-J 0.34.1 and earlier allows remote attackers to crash AMQP applications before authentication. The AMQP decoder recursively processes attacker-controlled nested types without a nesting-depth limit, exhausting the Java call stack and raising StackOverflowError. Any network-exposed application that embeds the library and accepts AMQP input before authentication can be interrupted; no data access or modification is reported.

CVSS severity7.5
High
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Uncontrolled recursion in Apache Qpid Proton-J 0.34.1 and earlier allows remote attackers to crash AMQP applications before authentication. The AMQP decoder recursively processes attacker-controlled nested types without a nesting-depth limit, exhausting the Java call stack and raising StackOverflowError. Any network-exposed application that embeds the library and accepts AMQP input before authentication can be interrupted; no data access or modification is reported.

The record

CVE
CVE-2026-66274
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
The Apache Software Foundation
Product
Apache Qpid Proton-J
Classifications
CWE-674, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=0 <=0.34.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Qpid Proton-Jversion=0 <=0.34.1

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-674Uncontrolled Recursion
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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