See What's New for details.
This is a bug fix release for 2.6.0 where the "TuDoor" fix erroneously
suppressed legitimate Truncated exceptions. This caused the stub
resolver to timeout instead of failing over to TCP when a legitimate
truncated response was received over UDP.
This release addresses the potential DoS issue discussed in the
"TuDoor" paper (CVE-2023-29483). The dnspython stub resolver is
vulnerable to a potential DoS if a bad-in-some-way response from the
right address and port forged by an attacker arrives before a
legitimate one on the UDP port dnspython is using for that query. In
this situation, dnspython might switch to querying another resolver or
give up entirely, possibly denying service for that resolution. This
release addresses the issue by adopting the recommended mitigation,
which is ignoring the bad packets and continuing to listen for a
legitimate response until the timeout for the query has expired.
Thank you to all the contributors to this release, and, as usual,
thanks to my co-maintainers: Tomáš Křížek, Petr Špaček, and Brian
Wellington.