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HIGH

CVE-2026-66273

CVSS v3

7.5

HIGH

EPSS Score

0.8 %

exploit probability, as of 2026-10-17

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2026-66273 Red Hat Product Security7 products fixed · 2 known affected

    org.apache.qpid/proton-j: Apache Qpid Proton-J: Denial of Service due to excessive allocation

    proton-j as a component of Red Hat build of Apache Camel 4 for Quarkus 3 · proton-j as a component of Red Hat JBoss Enterprise Application Platform Expansion Pack

  • RHSA-2026:71675 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat Build of Apache Camel 4.18.4 for Spring Boot release.

  • RHSA-2026:69459 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: AMQ Clients 2026.Q3

  • RHSA-2026:66545 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat AMQ Broker 7.13.6 release and security update

  • RHSA-2026:66488 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat AMQ Broker 7.14.1 release and security update

  • RHSA-2026:63302 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat Build of Apache Camel 4.18 for Quarkus 3.33 update is now available (RHBQ 3.33.3.SP1)

2 more advisories

Full record on NVD

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.

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-08-05
Last Modified
2026-08-06

Frequently asked questions

What is CVE-2026-66273?

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.

Is CVE-2026-66273 actively exploited?

Active exploitation of CVE-2026-66273 has not been confirmed. Its EPSS score was 0.8% on 2026-10-17, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-66273?

CVE-2026-66273 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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