How to Fix CVE-2024-27834 in Apple Safari

The two-minute check

1. Open Apple Safari's About or Settings screen and note the version number.
2. Check whether any work devices run the operating system labeled macOS, iPadOS, iPhone OS, tvOS, or watchOS.
3. Write down the exact version shown on each device you check.
4. Compare those versions against the fixed versions listed in the vendor advisories linked below.

When you can stop reading

If nobody in your business uses Apple Safari, or a device running macOS, iPadOS, iPhone OS, tvOS, or watchOS, this bug does not apply to you. You can close this tab. If you do use any of that software, keep reading.

What the official record says

The National Vulnerability Database (NVD) scores this flaw 5.5 out of 10, rated MEDIUM, using the Common Vulnerability Scoring System (CVSS) version 3.1 (NVD). The scoring details say an attacker needs local access to the device and already needs some low-level login privileges. The attack does not require the user to click anything or take any action. If successful, it can alter data integrity on the device, but it does not expose data or crash the device outright.

The probability of exploitation in the next 30 days is 0.598 percent, placing it at the 48.75th percentile among scored vulnerabilities (EPSS). The Exploit Prediction Scoring System (EPSS) is a forecast of exploitation activity, not a measure of how damaging the flaw is. Taken together, that is a low chance of exploitation in the next 30 days.

This flaw is also listed on the Known Exploited Vulnerabilities (KEV) catalog maintained by the Cybersecurity and Infrastructure Security Agency, which means criminals are already using it in real attacks (CISA KEV).

What that means for a business like yours

The fix was built to stop an attacker from bypassing a check called Pointer Authentication. That check normally blocks attackers from hijacking a program by tampering with the internal memory addresses it relies on. Because this attack needs local access and some existing login rights, the realistic scenario is a device that has already been compromised in some other way. This flaw lets that attacker go further on that same device, rather than letting a stranger break in from the internet.

If someone else manages your IT

Send your provider a short, specific request. You can paste this in:

"Please confirm whether CVE-2024-27834 affects any of our Apple Safari or Apple device deployments. Please apply the vendor-listed fix to any affected device. Please confirm when that work is done."

If you manage it yourself

1. Open the Settings or System Preferences app on the device.
2. Find the software update section.
3. Check whether an update is available and what version it installs.
4. Review the matching vendor advisory for your device type: Safari update, iPhone OS and iPadOS update, iPhone OS and iPadOS update (newer line), macOS update, tvOS update, or watchOS update.
5. Install the update shown on that advisory.
6. Restart the device if it asks you to.
7. Repeat this on every device your business owns that runs this software.

If you want a second set of hands on this, our managed IT services team can run this check across every device you own.

This flaw is already on the Known Exploited Vulnerabilities (KEV) catalog, with a federal remediation due date of November 18, 2026 (CISA KEV). For a business, the honest answer is now. The fix already exists, so there is no reason to wait for a more convenient week.

Do not just trust the install screen. Go back into the Settings or System Preferences app once the device finishes restarting. Check the version number again. Compare it against the version named in the matching advisory linked above. If the numbers match, the update applied correctly.

If you cannot update today, there are steps that reduce risk while you wait. None of them replace the patch, but each one buys you some time.

• Require a screen lock and a strong passcode on every affected device. This does not stop the flaw, but it raises the bar for the local access the attack needs.
• Limit who has administrator or elevated login rights on these devices. Our privileged access management guidance explains how to tighten that safely.
• Keep an eye on device activity through your monitoring tools. Automated 24/7 monitoring does not patch the device, but it can flag unusual behavior sooner.
• If these devices handle regulated data, check your obligations under rules like the HIPAA or the FTC Safeguards Rule while you plan the update.

Do I have to do anything if we only use this software at home?

This guide is written for business use, but the same fix applies at home. If a personal device runs the affected software, the same check and update steps apply there too.

Will this update break anything else on the device?

The record does not say anything about compatibility problems. Vendor updates like this one are routine maintenance, and the advisories linked above describe exactly what each update changes.

Do we need to do this on every single device, or just the main ones?

Check every device that runs Apple Safari or the listed operating systems, not just the ones your team uses daily. A device sitting unused in a drawer is still a device an attacker could reach if it has local access.

How do we know if someone has already used this against us?

The record does not include indicators of compromise you can search for yourself. If you suspect a device has already been tampered with, treat it as a security incident and get it reviewed rather than waiting on this update alone.

What if we don't have anyone in-house who handles this kind of thing?

That is a common situation, and it is exactly what our cybersecurity team handles for businesses with no dedicated IT staff. With 20+ years of experience and 100% U.S.-based support, we can check your environment and apply this fix for you. Request a free IT assessment or contact us to get started.