CVE-2019-19331
CVSS v3
7.5
HIGH
EPSS Score
2.2 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
knot-resolver before version 4.3.0 is vulnerable to denial of service through high CPU utilization. DNS replies with very many resource records might be processed very inefficiently, in extreme cases taking even several CPU seconds for each such uncached message. For example, a few thousand A records can be squashed into one DNS message (limit is 64kB).
Technical details
- Published
- 2019-12-16
Frequently asked questions
What is CVE-2019-19331?
knot-resolver before version 4.3.0 is vulnerable to denial of service through high CPU utilization. DNS replies with very many resource records might be processed very inefficiently, in extreme cases taking even several CPU seconds for each such uncached message. For example, a few thousand A records can be squashed into one DNS message (limit is 64kB).
Is CVE-2019-19331 actively exploited?
Active exploitation of CVE-2019-19331 has not been confirmed. Its EPSS score was 2.2% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2019-19331?
CVE-2019-19331 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2019-19331 affecting your environment?
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