GCVE-110-MAGEIA-2026-565

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.