Mac bugs and fixes October 30 2026: current status
Chapters
What broke when macOS 27.2 was installed?
Mezha says macOS 27.2 installed only after Lockdown Mode was temporarily disabled. The report describes a 15-inch MacBook Air M5 returning to macOS 27.1, build 26A434, after repeated downloads, installation attempts, and restarts. No clear error appeared onscreen.
The same report records rollbacks through System Settings, Safe Mode, the Install macOS 27 Golden Gate app, a bootable USB drive, and a DFU Revive. System Information showed the internal drive’s SMART status as "Verified" and TRIM as enabled. An APFS structure check found no errors. Apple Diagnostics found no hardware issue.
The Mac worked reliably during everyday use, according to the report. The failure appeared only during the system update. I read that result as a specific installation failure. I would not treat it as sufficient evidence for erasing the Mac or replacing its hardware.
Apple has not confirmed why changing Lockdown Mode allowed installation, the report says. No confirmed macOS update fix for that behavior has shipped. Temporarily changing the setting is a workaround, not a diagnosis. Its practical cost is changing a security setting for the update attempt and restoring it afterward. Among today’s Mac known issues, that distinction matters.
TL;DR
macOS 27.2 silently rolled back with Lockdown Mode enabled, according to Mezha, published October 29, 2026; OS X Daily, published October 26, 2026, documented dasd at 100% CPU. SecurityWeek, published October 27, 2026, says macOS 27.2 fixes 163 flaws; MacRumors, published October 25, 2026, says the command-line certificate fix remains unshipped.
- Mezha installed macOS 27.2 after temporarily disabling Lockdown Mode.
- SecurityWeek says macOS 27.2 fixes 163 security flaws.
- OS X Daily reduced dasd from 100% CPU to 0% by resetting its PowerLog database and restarting.
- MacRumors says Apple has not shipped the additional certificate fix for affected command-line tools.
Which macOS fixes have already shipped?
SecurityWeek says macOS 27.2 fixes 163 flaws. Its report says the newest iOS and macOS releases address 286 vulnerabilities in total. Roughly 140 security holes are shared across the operating systems.
The Apple security update repairs memory-corruption flaws in WebKit, the kernel, and components that handle images, fonts, PDFs, audio, and video files, according to the report. Some flaws could allow arbitrary code execution. Others affected sensitive data, privacy preferences, sandboxing, Gatekeeper, Screen Sharing, Remote Management, and SMB.
The report also identifies more than a dozen privilege-escalation flaws in macOS 27.2. Some could give apps root access. It describes remotely or locally reachable problems in Screen Sharing, Remote Management, and SMB. A Remote Management flaw could allow arbitrary code execution.
SecurityWeek does not name a macOS build for these repairs. I will not attach build 26A434 to them because Mezha identifies that build as macOS 27.1. The shipped repairs justify installing macOS 27.2 after making a backup. They do not establish that Apple repaired the separate Lockdown Mode installation behavior.
Has Apple closed the eMudhra certificate gap?
MacRumors says Apple has not shipped the additional fix for affected macOS command-line tools. Its report says Apple has blocked eMudhra’s compromised TLS web certificates since October 19 in Safari, Mail, and apps using Apple’s networking and security frameworks.
The report says weak private cryptographic keys were associated with eight intermediate certificate authority certificates. The keys could have allowed attackers to impersonate legitimate websites and potentially expose sensitive information. It also says there was no evidence that attackers had used the keys maliciously.
The automatic block requires no software update for most Apple device owners, according to the report. Some macOS command-line tools can still accept the compromised certificates. Apple plans a macOS update containing an additional fix, but that repair has not shipped.
The report directs affected administrators to Apple’s support document for cert.pem details. It does not reproduce the complete procedure, so I will not invent a command. Until Apple ships the repair, I recommend avoiding affected command-line tools for TLS connections when the workflow can wait. The cost is pausing those command-line workflows. Administrators who cannot wait should follow Apple’s linked procedure exactly and back up cert.pem first.
Why can dasd stay at 100% CPU?
OS X Daily says resetting the PowerLog database and restarting returned dasd to 0% CPU. The article describes dasd consuming 100% CPU for several days, with observed use hovering between 90-100% CPU. It associates that load with significant battery drain and resource misallocation.
Activity Monitor, a normal restart, and Safe Mode did not stop the load, according to the article. Its troubleshooting suggested a possible connection to telemetry and the PowerLog background-processing database in macOS 27 Golden Gate. That explanation is tentative rather than an Apple diagnosis.
The successful procedure backed up the PowerLog database, erased it, and restarted the Mac. The article warns that the Terminal steps delete a system file that is actively being written. Something could go wrong. It says to make a Time Machine backup before proceeding.
I would use the article’s exact commands rather than reconstructing them from a summary. After restarting, check CPU use once the Mac settles and again after 10 minutes, as the article instructs. The workaround costs troubleshooting time and carries the risk of deleting a system file. Skip it without a complete backup.
What can a Mac user do today?
Back up the Mac, install macOS 27.2, and use the narrow workaround that matches the observed failure. SecurityWeek says macOS 27.2 contains 163 shipped security repairs. Open Software Update after confirming that a current backup can be opened.
If installation repeatedly returns the Mac to macOS 27.1 and Lockdown Mode is enabled, temporarily disable that setting. Retry the update. Enable Lockdown Mode again after installation. Keep the change limited to the update attempt. Apple has not confirmed why the workaround succeeded.
Do not erase a working Mac solely because the update rolled back. Record the installed version and build. Preserve the update logs. If dasd remains at 100% CPU, verify the process in Activity Monitor before considering the PowerLog procedure. Follow the linked instructions only with a complete backup.
Command-line users should determine whether their work accepts TLS certificates through an affected tool. Pause that workflow or follow Apple’s cert.pem guidance until the additional macOS repair ships. Other users can use Safari, Mail, or apps covered by Apple’s automatic block. I am treating these macOS bugs separately because each has a different fix status. Compare the previous Mac bugs and fixes October 29 2026: what shipped before changing an installation plan.