CVE-2024-6874: Haxx Libcurl

Medium severity, CVSS 4.3. EPSS: 0.8% chance of exploitation in the next 30 days.

libcurl's URL API function [curl_url_get()](https://curl.se/libcurl/c/curl_url_get.html) offers punycode conversions, to and from IDN. Asking to convert a name that is exactly 256 bytes, libcurl ends up reading outside of a stack based buffer when built to use the *macidn* IDN backend. The conversion function then fills up the provided buffer exactly - but does not null terminate the string. This flaw can lead to stack contents accidently getting returned as part of the converted string.

Affected products

• Haxx Libcurl: version 8.8.0 only

Published 2024-07-24. Last modified 2026-06-17.