Apple CVE-2024-27834: CISA's deadline is November 18

CISA added CVE-2024-27834 to the Known Exploited Vulnerabilities catalog on November 4, 2026. Federal civilian agencies have until November 18, 2026 to apply Apple’s fix under Binding Operational Directive 26-04. Everyone else is on the same devices and the same lag.

Apple fixed the flaw in May 2024. The builds that close it are Safari 17.5, iOS 16.7.8 and iPadOS 16.7.8, iOS 17.5 and iPadOS 17.5, macOS Sonoma 14.5, tvOS 17.5, and watchOS 10.5, plus anything newer that inherited those checks. The published score is 5.5, medium. CISA listed it because there is evidence of active exploitation. The catalog marks ransomware use as unknown and does not require forensic triage. A medium score with a KEV date is still a patch-now item.

A May 2024 fix, back on the board

Public descriptions call CVE-2024-27834 an authentication failure in pointer checks. An attacker who can already read and write memory can skip a control Apple uses to reject forged pointers. It is a step after a foothold, which is why the score stays moderate, and it is still the step that turns a memory primitive into code the device will trust. The Hacker News reports that the bug was shown as a zero-day at Pwn2Own Vancouver in March 2024, before Apple’s May updates.

CISA’s own alert names the vulnerability and the fact of exploitation. It does not name malware or an operator. The Hacker News tied the listing to research on information-stealing malware delivered through Apple browser flaws vendors had already patched. That attribution is not required to run the response. Devices still sitting under the May 2024 line are the population that matters.

What to do before November 18

Inventory iPhone, iPad, Mac, Safari, Apple TV, and Apple Watch in one pass. Confirm the build, not the date on a help-desk ticket. A Mac that updates Safari on its own can be behind even when the operating system looks current. Raise the MDM minimum to the fixed releases or later. Federal teams should follow the BOD 26-04 order: vendor update, or take the asset out of service if the update cannot be applied.

For any device that was still below those builds while the bug was listed as exploited, assume browser sessions on that device are exposed. Sign the user out, rotate the passwords those browsers held, and reissue tokens for mail, cloud consoles, and developer accounts. A Watch or an Apple TV that is signed into a corporate Apple ID belongs in the same list.

Skip the temptation to treat 5.5 as a reason to wait. The patch has been shipping for a year and a half. November 18 is the federal due date. The operational date is the day a managed device is still on the wrong side of Safari 17.5, iOS 17.5, or Sonoma 14.5.

This briefing relies on public reporting by The Hacker News, on CISA’s November 4, 2026 KEV alert, and on the National Vulnerability Database entry for CVE-2024-27834.