CVE-2026-19553

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped. This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration. If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability. Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.

Python combines remarkable power with very clear syntax. It has modules, classes, exceptions, very high level dynamic data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems. New built-in modules are easily written in C or C++ (or other languages, depending on the chosen implementation). Python is also usable as an extension language for applications written in other languages that need easy-to-use scripting or automation interfaces.

Security Fix(es):

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.(CVE-2026-19553)

Python combines remarkable power with very clear syntax. It has modules, classes, exceptions, very high level dynamic data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems. New built-in modules are easily written in C or C++ (or other languages, depending on the chosen implementation). Python is also usable as an extension language for applications written in other languages that need easy-to-use scripting or automation interfaces.

Security Fix(es):

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.(CVE-2026-19553)

Python combines remarkable power with very clear syntax. It has modules, classes, exceptions, very high level dynamic data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems. New built-in modules are easily written in C or C++ (or other languages, depending on the chosen implementation). Python is also usable as an extension language for applications written in other languages that need easy-to-use scripting or automation interfaces.

Security Fix(es):

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.(CVE-2026-19553)

Python combines remarkable power with very clear syntax. It has modules, classes, exceptions, very high level dynamic data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems. New built-in modules are easily written in C or C++ (or other languages, depending on the chosen implementation). Python is also usable as an extension language for applications written in other languages that need easy-to-use scripting or automation interfaces.

Security Fix(es):

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.(CVE-2026-19553)

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)

• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)

• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)

• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)

• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)

• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Arbitrary file deletion via race condition during temporary directory cleanup (CVE-2026-12345)

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)

• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Arbitrary file deletion via race condition during temporary directory cleanup (CVE-2026-12345)

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)

• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped. This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration. If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability. Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)
• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)
• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)
• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)
• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)
• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Arbitrary file deletion via race condition during temporary directory cleanup (CVE-2026-12345)
• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)
• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems.

Security Fix(es):

• python: python: Arbitrary file deletion via race condition during temporary directory cleanup (CVE-2026-12345)
• python: python: Certificate verification bypass via missing server_hostname validation in SSLContext.wrap_bio() (CVE-2026-19553)
• python: Use-after-free of a server-side SSLContext when sni_callback switches contexts (CVE-2026-19445)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.

ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped.

This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration.

If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability.

Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied.

• CVE-2026-19445: ssl: resolve the SSLContext for the SNI servername callback from the connection instead of the borrowed SSL_CTX argument, and unregister the callback in context_dealloc, so a context dropped after sni_callback switched the connection is no longer used after it is freed
• CVE-2026-19553: ssl: validate SSLContext.wrap_bio() arguments in SSLObject._create the way wrap_socket() does - reject server_hostname and session in server mode, and emit a DeprecationWarning when check_hostname is enabled but no server_hostname is given, surfacing the misconfiguration that made certificate hostname verification be skipped silently

• SECURITY UPDATE: hostname verification silently skipped by SSLContext.wrap_bio() when no server_hostname is given
  • debian/patches/CVE-2026-19553.patch: in Lib/ssl.py, validate the wrap_bio() arguments like wrap_socket() does: reject server_hostname and session in server mode, and emit a DeprecationWarning when check_hostname is enabled but server_hostname is None, so a client that verified the certificate chain but never the peer's identity is no longer silent about it (asyncio's create_connection()/start_tls() reach this path too). Backport of upstream commit 5867d4e4ae6d (gh-156793 / GH-158503, 3.10 branch, which warns instead of raising ValueError for backward compatibility). Bundles the upstream regression tests (test_ssl.py, test_sslproto.py), adapted to the 3.7 test.support API.
  • CVE-2026-19553
• SECURITY UPDATE: use-after-free in the SSL servername (SNI) callback
  • debian/patches/CVE-2026-19445.patch: in Modules/_ssl.c, look the SSLContext up from the connection instead of the borrowed pointer registered with OpenSSL, hold strong references to it and to the callback while they are used, and unregister the callback when the context is deallocated, so a TLS client can no longer make a server call through a freed SSLContext after sni_callback switched the connection to another context. Backport of upstream commit ec44b5a3258c (gh-156293 / GH-158504, 3.10 branch); Py_NewRef() is replaced by Py_INCREF() for 3.7. Bundles the upstream regression tests (test_ssl.py), adapted to the 3.7 test.support API.
  • CVE-2026-19445

• CVE-2026-19445: prevent a use-after-free in server-side SSLContext SNI callbacks
• CVE-2026-19553: validate SSLContext.wrap_bio() hostname and server-side parameters

• CVE-2026-19445: prevent use-after-free in the TLS server name callback when switching SSL contexts
• CVE-2026-19553: validate SSLObject server hostname and session parameters before wrapping memory BIOs

• CVE-2026-19553: ssl: SSLObject._create(), used by SSLContext.wrap_bio(), now emits a DeprecationWarning when check_hostname is enabled and server_hostname is None, and rejects server_hostname or session in server mode with ValueError, as wrap_socket() does

CVE-2026-12345 The cleanup of tempfile.TemporaryDirectory is vulnerable to a race condition. An attacker who can modify the tree during cleanup can replace a directory with a symbolic link, causing files outside of the temporary directory to be deleted or have their permissions and file flags reset, with the privileges of the process performing the cleanup. Note that platforms where shutil.rmtree.avoids_symlink_attacks is false, remain affected, and file flags may still be reset outside of the tree on all platforms. CVE-2026-19553 ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped. This defect could lead to programs where certificate hostname verification appeared to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration. If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability. Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied. CVE-2026-19445 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. CVE-2026-114583 tarfile.tar_filter could be bypassed using crafted link entries, including symlinks with empty or directory-like names, to redirect later archive members outside the intended extraction directory. This allowed a malicious tar archive to cause tarfile.extractall() with filter="tar" to write files outside the destination directory, subject to the permissions of the extracting process. This is the tarfile.tar_filter counterpart of CVE-2026-7774, which covered tarfile.data_filter.

These are all security issues fixed in the python315-3.15.0~rc3-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python310-3.10.22-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python311-3.11.17-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python312-3.12.15-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the python313-3.13.16-1.1 package on the GA media of openSUSE Tumbleweed.