CVE-2026-19445
CRITICAL 1 PoC
INFO
Priority: 0.05
BB Relevance:
79/100
Published: 2026-09-30
Modified: 2026-11-10
First seen: 2026-11-09
Status: active
Attack Surface
Network
No Auth
No Interaction
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
None
UI:
None
S:
X
AT:
Present
VC:
High
VI:
High
VA:
Low
Description
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.
Weakness Classification (1)
Affected Software (12)
| Vendor | Product | Version |
|---|---|---|
| Python Software Foundation | CPython | 0 < 3.10.22 |
| Python Software Foundation | CPython | 3.11.0 < 3.11.17 |
| Python Software Foundation | CPython | 3.12.0 < 3.12.15 |
| Python Software Foundation | CPython | 3.13.0 < 3.13.16 |
| Python Software Foundation | CPython | 3.14.0 < 3.14.8 |
| Python Software Foundation | CPython | 3.15.0a1 < 3.15.0rc3 |
| Python Software Foundation | CPython | 0 < 3.10.22 |
| Python Software Foundation | CPython | 3.11.0 < 3.11.17 |
| Python Software Foundation | CPython | 3.12.0 < 3.12.15 |
| Python Software Foundation | CPython | 3.13.0 < 3.13.16 |
| Python Software Foundation | CPython | 3.14.0 < 3.14.8 |
| Python Software Foundation | CPython | 3.15.0a1 < 3.15.0rc3 |
References & Advisories (12)
vendor-advisory
patch
patch
patch
patch
patch
patch
patch
patch
issue-tracking