Sparkle is a software update framework for macOS. In versions up to and including 2.9.1, Autoupdate/AppInstaller.m's shouldAcceptNewConnection: only enforces SUCodeSigningVerifier validateConnection: before stage 1 completes. After _performedStage1Installation = YES, new connections to the registered Mach service <bundleId>-spki are accepted from any local process without team-ID or code-signing checks. As of time of publication, no known patched versions are available.