CVE-2021-22945
CVSS v3
9.1
CRITICAL
EPSS Score
6.7 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.
Technical details
- Published
- 2021-09-23
Frequently asked questions
What is CVE-2021-22945?
When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.
Is CVE-2021-22945 actively exploited?
Active exploitation of CVE-2021-22945 has not been confirmed. Its EPSS score was 6.7% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-22945?
CVE-2021-22945 has a CVSS v3 base score of 9.1 (CRITICAL severity).
Is CVE-2021-22945 affecting your environment?
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