CVE-2026-19445 (GCVE-0-2026-19445)
Vulnerability from cvelistv5
Published
2026-09-30 16:16
Modified
2026-10-03 00:36
Severity ?
9.2 (Critical) - CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
CWE
Summary
A remote, unauthenticated TLS client can make a server crash or call through a freed pointer if its sni_callback assigns a different context to SSLSocket.context (the documented way to select a certificate per server name) and nothing else keeps the original ssl.SSLContext alive. Typical cases are servers that create an SSLContext per connection or replace it while connections are open; servers that wrap their listening socket with it are not affected. Mitigation: keep a reference to every SSLContext that sets sni_callback for the lifetime of the server. TLS clients are not affected.
References
Impacted products
Vendor Product Version
Python Software Foundation CPython Version: 0
Version: 3.11.0
Version: 3.12.0
Version: 3.13.0
Version: 3.14.0
Version: 3.15.0a1
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