CPython 3.9 and earlier doesn't disallow configuring an empty list ("[]") for SSLContext.setnpnprotocols() which is an invalid value for the underlying OpenSSL API. This results in a buffer over-read when NPN is used (see CVE-2024-5535 for OpenSSL). This vulnerability is of low severity due to NPN being not widely used and specifying an empty list likely being uncommon in-practice (typically a protocol name would be configured).
{
"cna_assigner": "PSF",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/5xxx/CVE-2024-5642.json"
}