CVE-2026-84487 Overview
CVE-2026-84487 is an integer overflow vulnerability [CWE-190] affecting multiple Apple operating systems. Processing a maliciously crafted file may result in disclosure of process memory. Apple addressed the issue with improved input validation across its OS lineup.
The flaw impacts iOS, iPadOS, macOS, tvOS, visionOS, and watchOS. An attacker can exploit the vulnerability over the network by convincing a user to open or process a malicious file. Successful exploitation exposes sensitive in-memory data such as pointers, tokens, or cryptographic material that can enable follow-on attacks.
Critical Impact
Attackers can leak process memory from affected Apple devices by delivering a crafted file, exposing sensitive data across the entire Apple ecosystem.
Affected Products
- Apple iOS and iPadOS (fixed in iOS 26.7, iPadOS 26.7, iOS 27, and iPadOS 27)
- Apple macOS (fixed in macOS Sequoia 15.8, macOS Tahoe 26.7, and macOS Golden Gate 27)
- Apple tvOS 27, visionOS 27, and watchOS 27
Discovery Timeline
- 2026-09-14 - CVE-2026-84487 published to the National Vulnerability Database (NVD)
- 2026-09-16 - Entry last modified in the NVD database
Technical Details for CVE-2026-84487
Vulnerability Analysis
CVE-2026-84487 is an integer overflow condition triggered during the parsing of a crafted file. When affected Apple code processes attacker-controlled input, an arithmetic operation exceeds the storage capacity of its integer type. The resulting truncated value is then used to size or index a memory buffer.
Because the calculation underpins buffer boundary logic, subsequent read operations reference memory outside the intended structure. The out-of-bounds read returns adjacent heap or stack contents to the attacker-influenced parser. The disclosed bytes can include pointers, session material, or fragments of previously processed data useful for bypassing address space layout randomization (ASLR) and staging further exploitation.
Root Cause
The root cause is missing bounds validation on integer arithmetic used during file parsing. Apple's advisories describe the fix as "improved input validation," which is consistent with the classification under [CWE-190] Integer Overflow or Wraparound. Prior to the patch, the parser trusted length or offset fields that could wrap when multiplied or added.
Attack Vector
Exploitation requires user interaction to process a maliciously crafted file. Delivery channels include email attachments, messaging applications, web downloads, and shared documents opened by any application that invokes the vulnerable parser. The attack is network-reachable and requires no authentication or elevated privileges.
No public proof-of-concept exploit is available at the time of publication, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Technical exploitation details are not published in the vendor advisories; see the Apple Security Advisories for the affected component information.
Detection Methods for CVE-2026-84487
Indicators of Compromise
- Anomalous crash reports or ReportCrash entries referencing file parsing components after a user opens an untrusted document or media file.
- Unexpected outbound network traffic from applications immediately following the handling of an inbound file from email, messaging, or web sources.
- Presence of malformed files with abnormally large length or size fields designed to trigger arithmetic overflow during parsing.
Detection Strategies
- Inventory Apple endpoints and compare installed OS build numbers against the fixed versions listed in the Apple advisories to identify exposed devices.
- Hunt for processes that read attacker-controlled files and subsequently exhibit unusual memory-read patterns or crashes indicative of out-of-bounds access.
- Correlate file delivery events (email gateway, web proxy, messaging clients) with subsequent process anomalies on the receiving endpoint.
Monitoring Recommendations
- Enable and centralize macOS unified logs and iOS device management telemetry to capture crash traces from file-handling processes.
- Monitor endpoint detection and response (EDR) telemetry for repeated process crashes tied to specific file types across the fleet.
- Track user-reported document rendering failures, which may indicate opportunistic probing of the flaw.
How to Mitigate CVE-2026-84487
Immediate Actions Required
- Update all Apple devices to the fixed releases: iOS 26.7, iPadOS 26.7, iOS 27, iPadOS 27, macOS Sequoia 15.8, macOS Tahoe 26.7, macOS Golden Gate 27, tvOS 27, visionOS 27, and watchOS 27.
- Prioritize patching devices that regularly process untrusted files from external sources such as email, chat platforms, or web downloads.
- Instruct users to avoid opening files from unverified senders until patching is complete.
Patch Information
Apple has released fixes across its operating system lineup. Refer to the vendor bulletins for build-specific guidance: Apple Security Advisory #149034, #149035, #149036, #149037, #149038, #149041, #149042, and #149043.
Workarounds
- No vendor-supplied workaround exists. Apply the security update as the sole remediation path.
- Restrict inbound file types at email and web gateways where feasible to reduce attacker delivery options until patches are deployed.
- Enforce mobile device management (MDM) policies that require minimum OS versions before permitting corporate resource access.
# Verify current macOS version and check for available updates
sw_vers -productVersion
sudo softwareupdate --list
sudo softwareupdate --install --all --restart
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.