libcurl's URL API function curlurlget() 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 accidentally getting returned as part of the converted string.
{ "www": "https://curl.se/docs/CVE-2024-6874.html", "CWE": { "id": "CWE-126", "desc": "Buffer Over-read" }, "URL": "https://curl.se/docs/CVE-2024-6874.json", "package": "curl", "severity": "Low", "award": { "currency": "USD", "amount": "540" }, "issue": "https://hackerone.com/reports/2604391", "affects": "lib", "last_affected": "8.8.0" }