CVE-2026-67591
Description
A flaw was found in Apache Qpid ProtonJ2. An authenticated attacker can exploit this vulnerability by exceeding the session flow control incoming window. This can lead to a denial of service (DoS), making the system unavailable to legitimate users.
Statement
Red Hat ships Apache Qpid ProtonJ2 components (protonj2-parent, protonj2-test-driver) in AMQ Broker 7. The affected components are set to AFFECTED/DEFER as the CVSS score (6.5) is below the 7.0 threshold for immediate remediation. Note: the substring-matched artifacts are ancillary (parent POM, test driver) — the core protonj2-client library was not found via strict search. The affects are precautionary.
Mitigation
Ensure authenticated access to AMQP endpoints is restricted to trusted clients to limit exposure to this DoS vulnerability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
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