* SECURITY UPDATE: the import machinery read legacy .pyc files through a plain file object rather than io.open_code(). FileLoader.get_data() special-cased only SourceLoader and ExtensionFileLoader, so a sourceless import never raised the "open_code" audit event and audit hooks could neither observe nor veto the file being read. - debian/patches/CVE-2026-2297.patch: backport of cpython a51b1b51 (gh-145506, 3.13 branch). SourcelessFileLoader is added to the isinstance() check, so .pyc loads go through io.open_code() like every other import path. - CVE-2026-2297 * SECURITY UPDATE: positional predicates in xml.etree.ElementPath rebuilt the parent's child list once for every candidate element, so an expression such as ".//tag[last()]" cost time quadratic in the number of matches and an attacker-supplied document could drive a CPU denial of service. - debian/patches/CVE-2026-6879.patch: backport of cpython 2ffab083 (gh-152674). The (parent, tag) sibling lookup is now memoised for the duration of the selection. - CVE-2026-6879 * SECURITY UPDATE: base64.b64decode() and base64.urlsafe_b64decode() silently accepted the standard "+" and "/" characters even when an alternative alphabet was in use, reinterpreting them instead of rejecting them, so two different inputs could decode to the same bytes. - debian/patches/CVE-2025-12781.patch: backport of cpython 9060b4ab (gh-125346). Both functions now emit a DeprecationWarning in strict mode and a FutureWarning otherwise, and a malformed altchars raises ValueError instead of tripping an assertion that disappears under -O. Decoded output is unchanged. - CVE-2025-12781