How severe is CVE-2026-66277?

CVE-2026-66277 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-66277 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-66277?

CVE-2026-66277 affects Apache Qpid Proton-j. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-66277?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-66277 published?

CVE-2026-66277 was published on 2026-08-05 and last updated on 2026-08-07.

CVE-2026-66277

CVE-2026-66277 is a medium-severity vulnerability in Apache Qpid Proton-j with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Apache Qpid Proton-j
Published: 2026-08-05
Last modified: 2026-08-07

Description

It was not possible to govern the maximum number of transfer frames per incoming delivery, enabling an authenticated attacker to cause excessive resource usage and 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.

Frequently asked questions

What is CVE-2026-66277?: It was not possible to govern the maximum number of transfer frames per incoming delivery, enabling an authenticated attacker to cause excessive resource usage and 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.
How severe is CVE-2026-66277?: CVE-2026-66277 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-66277 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-66277?: CVE-2026-66277 affects Apache Qpid Proton-j. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-66277?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-66277 published?: CVE-2026-66277 was published on 2026-08-05 and last updated on 2026-08-07.

References

Affected products (1)

cpe:2.3:a:apache:qpid_proton-j:*:*:*:*:*:*:*:*

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