CVE-2019-3823: High severity haxx libcurl vulnerability
Last updated 25 August 2025
Other sources
libcurl versions from 7.34.0 to before 7.64.0 are vulnerable to a heap out-of-bounds read in the code handling the end-of-response for SMTP.
If the buffer passed to smtpendofresp() isn't NUL terminated and contains no character ending the parsed number, and len is set to 5, then the strtol() call reads beyond the allocated buffer. The read contents will not be returned to the caller.
Bug introduced by:
https://github.com/curl/curl/commit/2766262a68
— Red Hat
Affected Software
Remediation
Patch Available
Patch Available
Event History
Frequently Asked Questions
What is CVE-2019-3823?
CVE-2019-3823 is a vulnerability in libcurl versions from 7.34.0 to before 7.64.0 that allows for a heap out-of-bounds read in the code handling the end-of-response for SMTP.
How severe is CVE-2019-3823?
CVE-2019-3823 has a severity level of 7.5 (High).
Which software versions are affected by CVE-2019-3823?
The affected software versions include libcurl from 7.34.0 to before 7.64.0, curl 7.64.0-4+deb10u2, curl 7.64.0-4+deb10u7, curl 7.74.0-1.3+deb11u9, curl 7.74.0-1.3+deb11u10, curl 7.88.1-10+deb12u3, curl 7.88.1-10+deb12u4, and curl 8.4.0-2.
How can I fix CVE-2019-3823?
To fix CVE-2019-3823, it is recommended to update libcurl to version 7.64.0 or later.
Where can I find more information about CVE-2019-3823?
You can find more information about CVE-2019-3823 at the official CVE page: https://curl.haxx.se/docs/CVE-2019-3823.html