Apple iOS CVE-2026-43785

Exploitation requires an attacker to already have a local, low-privileged app running on the target Apple device (AV:L/PR:L); it is not remotely reachable and needs no user interaction at exploit time. The specific limiting factor is that the app must already possess read permission to the target file - the flaw only escalates that read access into write/modify capability, so it cannot grant access to files the app could not already open. It affects default configurations of the listed OS versions prior to patching (iOS/iPadOS <27, macOS <15.8/<26.7/<27, tvOS <27, visionOS <27), with no special feature toggle required.

This is a genuine but low-priority local integrity flaw, not a remotely exploitable emergency. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N, base 5.5) confirms it requires local access and existing low privileges - specifically, code already running on the device as an app. There is no network vector and no confidentiality or availability impact; the sole effect is integrity (writing to a file the app should only be able to read). All exploitation signals agree on 'low real-world urgency': EPSS is 0.20% (10th percentile), there is no CISA KEV listing (not actively exploited), and no public exploit code has been identified. Apple self-reported the issue and shipped fixes across its OS line, which is typical of internally-found privilege/permission hardening rather than an externally-weaponized bug. The one caveat: because the affected products (iOS/iPadOS/macOS/tvOS/visionOS) are ubiquitous, even a low-severity local flaw has an enormous install base, so it matters for high-value targets and sandbox-escape chains even though it is not a mass-exploitation threat on its own. Note the input Tag 'Authentication Bypass' conflicts with the actual weakness (CWE-863 authorization / permission bypass) - this modifies file permissions, it does not bypass authentication.

A malicious or compromised app installed on an Apple device abuses a permissions-enforcement gap to write to a file it was only granted read access to, corrupting or tampering with that file's contents. No public proof-of-concept exists and the issue requires the attacker to already have code executing locally, so realistic use is as one link in a larger sandbox-escape or persistence chain rather than a standalone attack.