Apple has issued a third Release Candidate of macOS Tahoe 26.7.1 for developer testing. The September 21, 2026 build is 25G313, giving testers another near-final version to evaluate before Apple decides whether to release the update publicly.
Apple’s official developer seed catalog was updated on September 21 and identifies macOS 26.7.1 build 25G313. Apple has not published detailed release notes naming user-facing changes in this RC.
A Release Candidate is a build Apple considers close to public release, but RC 3 is still prerelease software. Its arrival means Apple changed the candidate again after earlier testing. It does not confirm what changed, and Apple could issue another candidate if testing finds a blocking problem.
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What Apple has not confirmed
Apple has not provided a feature list, a fix list, security advisories, or a public release date for build 25G313. Security content is normally published when an update reaches customers, so it would be inaccurate to assign specific vulnerability fixes to this candidate now.
The earlier macOS 26.7 RC cycle followed the same maintenance-focused pattern. Our guide to the macOS 26.6 Release Candidate explains why a late-stage build can still differ from the final public update.
How testers can update
Eligible developers can open System Settings, choose General, then Software Update. If the build does not appear, open Beta Updates and select the appropriate macOS developer channel. Back up important files first and keep the Mac connected to power during installation.
Testers should confirm build 25G313 in General and About after the restart. Because this is the third candidate, app launches, sleep and wake, network access, external hardware, and managed-device policies are useful areas to recheck before reporting a regression through Feedback Assistant.
Our macOS beta installation guide covers enrollment and the Software Update controls. Everyone else should wait for the public release and its accompanying notes rather than install build 25G313 on a production Mac.
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