How severe is CVE-2023-5632?

CVE-2023-5632 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-5632 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-5632?

CVE-2023-5632 affects Eclipse Mosquitto. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-5632?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-5632 published?

CVE-2023-5632 was published on 2023-10-18 and last updated on 2026-06-17.

CVE-2023-5632

CVE-2023-5632 is a high-severity vulnerability in Eclipse Mosquitto with a CVSS 3.x base score of 7.5. 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-834.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-834
Affected product: Eclipse Mosquitto
Published: 2023-10-18
Last modified: 2026-06-17

Description

In Eclipse Mosquito before and including 2.0.5, establishing a connection to the mosquitto server without sending data causes the EPOLLOUT event to be added, which results excessive CPU consumption. This could be used by a malicious actor to perform denial of service type attack. This issue is fixed in 2.0.6

Frequently asked questions

What is CVE-2023-5632?: In Eclipse Mosquito before and including 2.0.5, establishing a connection to the mosquitto server without sending data causes the EPOLLOUT event to be added, which results excessive CPU consumption. This could be used by a malicious actor to perform denial of service type attack. This issue is fixed in 2.0.6
How severe is CVE-2023-5632?: CVE-2023-5632 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-5632 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-5632?: CVE-2023-5632 affects Eclipse Mosquitto. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-5632?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-5632 published?: CVE-2023-5632 was published on 2023-10-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:eclipse:mosquitto:2.0.5:*:*:*:*:*:*:*

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