CVE-2026-19445
criticalPriorität · verfolgen · 10EPSS 0.004 · 36. PerzentilExploit · PoCDEUSEPSS · bewertet 2026-10-22
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.
cvss
Technischer Schweregrad, 0–10. Eine Zeile je Quelle.
Basiswert 0–10 · höher = schwerwiegender · Vektor überfahren zum Auflösen⚠ Quellen uneinig · high–critical · 8.1–9.2
schwächen
Die CWE-Schwächeklassen, zu denen dies gehört.
Exploits (1)
Öffentlicher Proof-of-Concept- und Exploit-Code.
- abraxas/cve-2026-19445-sni-uafCPython - Critical - SNI SSLContext UAFPoC · poc_in_github
betroffene Produkte (23)
Betroffene Produkte und Versionsbereiche.
Advisories (5)
Hersteller- und Ökosystem-Meldungen dazu.
- WID-SEC-W-2026-3716CPython: Mehrere SchwachstellenDeutsch2026-10-01csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Python ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, um einen Denial of Service Angriff durchzuführen, und um Sicherheitsvorkehrungen zu umgehen.
- BIT-libpython-2026-19445Use-after-free of a server-side SSLContext when sni_callback switches contexts2026-10-09vendor · osvUS
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.
- BIT-python-2026-19445Use-after-free of a server-side SSLContext when sni_callback switches contexts2026-10-09vendor · osvUS
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.
- BIT-python-min-2026-19445Use-after-free of a server-side SSLContext when sni_callback switches contexts2026-10-09vendor · osvUS
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.
- PSF-2026-432026-09-30vendor · osvUS
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.
auch bekannt als (4)
Weitere Namen und Kennungen dieser Entität.
quellen
Welche Quellen diesen Datensatz belegen und wann.
Referenzen (11) nvd
Externe Belege — Patches, Meldungen, Analysen.
- http://www.openwall.com/lists/oss-security/2026/09/30/17
- https://github.com/python/cpython/commit/34a53dce8174da2fceb12fe084a4def02a10053d
- https://github.com/python/cpython/commit/46133cd57d309652139ada74014aca7665ac552b
- https://github.com/python/cpython/commit/63fab143d94cafae71850831acfb52041ba44af7
- https://github.com/python/cpython/commit/b12968cefe69ca1dcb8606c832ff73ee7dbf4ba8
- https://github.com/python/cpython/commit/cd7e51e7d4563866fbaa1e2521ae69b45daf3698
- https://github.com/python/cpython/commit/d8717ed01717a9641686e6e6f83f0ab8af235e2c
- https://github.com/python/cpython/commit/ec44b5a3258cbda947d5e07242ee562ed05ef24b
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