CVE-2026-84533 Overview
CVE-2026-84533 is a cryptographic vulnerability affecting multiple Apple operating systems. The flaw stems from insufficient integrity checks in a cryptographic routine, mapped to [CWE-353] Missing Support for Integrity Check. An attacker in a privileged network position on the same adjacent network segment may modify network traffic without detection.
Apple addressed the issue with improved integrity checks in iOS 27, iPadOS 27, macOS Golden Gate 27, tvOS 27, and watchOS 27. The vulnerability requires adjacent network access and high attack complexity, limiting mass exploitation potential.
Critical Impact
An attacker positioned on the adjacent network can tamper with cryptographically protected traffic, undermining the integrity guarantees of communications between affected Apple devices and their endpoints.
Affected Products
- Apple iOS (versions prior to iOS 27)
- Apple iPadOS (versions prior to iPadOS 27)
- Apple macOS (versions prior to macOS Golden Gate 27)
- Apple tvOS (versions prior to tvOS 27) and Apple watchOS (versions prior to watchOS 27)
Discovery Timeline
- 2026-09-14 - CVE-2026-84533 published to the National Vulnerability Database
- 2026-09-17 - Last updated in NVD database
Technical Details for CVE-2026-84533
Vulnerability Analysis
The vulnerability resides in a cryptographic component shared across Apple's operating system family. The affected code path failed to enforce sufficient integrity validation on data protected by cryptographic operations. This weakness maps to [CWE-353], which describes the absence of mechanisms to verify that transmitted data has not been altered.
Because the integrity check was incomplete, an attacker able to intercept and relay traffic could substitute or modify protected content. Apple's advisories confirm the fix was implemented by strengthening those integrity checks in the affected component.
Root Cause
Apple's advisory attributes the issue to insufficient cryptographic integrity validation. When a receiver processes protected messages without a robust integrity check, malformed or tampered payloads may be accepted as authentic. The corrected implementation adds stronger verification before trusting the data.
Attack Vector
Exploitation requires the attacker to hold a privileged network position. This typically involves control over a network segment adjacent to the victim device, such as a shared Wi-Fi network, a compromised router, or an on-path proxy. The attack complexity is high because the adversary must reliably intercept and modify traffic at the right moment while avoiding disruption to session state.
No user interaction and no prior authentication are required. The impact is limited to integrity of network traffic; confidentiality and availability are not directly affected according to the published CVSS vector.
No public proof-of-concept exploit or CISA KEV listing exists for this issue at the time of publication.
Detection Methods for CVE-2026-84533
Indicators of Compromise
- Unexpected TLS or protocol renegotiations on Apple client sessions originating from untrusted network segments
- Unusual ARP or DHCP activity on wireless segments used by Apple devices, indicating potential on-path positioning
- Certificate or key material mismatches observed in device system logs after connecting to public or shared networks
Detection Strategies
- Correlate Apple device inventory data with OS build versions to identify endpoints running pre-27 releases
- Monitor network telemetry for man-in-the-middle indicators such as duplicated MAC addresses or rogue gateway advertisements
- Baseline outbound cryptographic sessions from mobile fleets and alert on protocol downgrades or unexpected cipher negotiation
Monitoring Recommendations
- Ingest wireless infrastructure logs into a centralized analytics platform to detect rogue access points near Apple device populations
- Track Apple OS patch compliance through mobile device management (MDM) reporting and flag devices lagging behind current releases
- Enable network intrusion detection signatures for adjacent-network attack patterns targeting Apple protocols
How to Mitigate CVE-2026-84533
Immediate Actions Required
- Upgrade affected devices to iOS 27, iPadOS 27, macOS Golden Gate 27, tvOS 27, or watchOS 27 through MDM-enforced update policies
- Inventory all Apple devices in the environment and prioritize patching for those regularly connecting to untrusted networks
- Communicate risk guidance to mobile users, especially personnel traveling or using public wireless networks
Patch Information
Apple has released fixes across its OS family. Refer to the official Apple support documents for build numbers and installation guidance: Apple Support Document #149034, Apple Support Document #149035, Apple Support Document #149036, and Apple Support Document #149037.
Workarounds
- Restrict use of untrusted or public Wi-Fi networks on unpatched Apple devices; require VPN tunneling to a trusted concentrator
- Enforce certificate pinning and mutual TLS at application layers where feasible to add defense in depth against traffic modification
- Segment guest and corporate wireless networks and monitor for on-path attack indicators until all endpoints are updated
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
