How severe is CVE-2016-2166?

CVE-2016-2166 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.

Is CVE-2016-2166 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-2166?

CVE-2016-2166 primarily affects Apache Qpid Proton. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-2166?

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

When was CVE-2016-2166 published?

CVE-2016-2166 was published on 2016-04-12 and last updated on 2026-06-17.

CVE-2016-2166

CVE-2016-2166 is a medium-severity vulnerability in Apache Qpid Proton 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 5.8
EPSS exploit prediction: 4% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Apache Qpid Proton
Published: 2016-04-12
Last modified: 2026-06-17

Description

The (1) proton.reactor.Connector, (2) proton.reactor.Container, and (3) proton.utils.BlockingConnection classes in Apache Qpid Proton before 0.12.1 improperly use an unencrypted connection for an amqps URI scheme when SSL support is unavailable, which might allow man-in-the-middle attackers to obtain sensitive information or modify data via unspecified vectors.

Frequently asked questions

What is CVE-2016-2166?: The (1) proton.reactor.Connector, (2) proton.reactor.Container, and (3) proton.utils.BlockingConnection classes in Apache Qpid Proton before 0.12.1 improperly use an unencrypted connection for an amqps URI scheme when SSL support is unavailable, which might allow man-in-the-middle attackers to obtain sensitive information or modify data via unspecified vectors.
How severe is CVE-2016-2166?: CVE-2016-2166 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.
Is CVE-2016-2166 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-2166?: CVE-2016-2166 primarily affects Apache Qpid Proton. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-2166?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-2166 published?: CVE-2016-2166 was published on 2016-04-12 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:apache:qpid_proton:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*

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