Description

An authentication issue was addressed with improved state management. This issue is fixed in iOS 26.6.1 and iPadOS 26.6.1. An attacker in a privileged network position may be able to bypass IPSec authentication and intercept network traffic.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.9",
  "pubDate": "2026-08-17T22:17:23.830Z",
  "pubdate": "2026-08-17T22:17:23.830Z",
  "executiveSummary": "An authentication bypass vulnerability has been identified within the network stack of iOS and iPadOS, specifically stemming from inadequate state management during protocol handshakes.\nThe vulnerability allows an adversarial actor positioned in a privileged network location to successfully circumvent standard IPSec authentication mechanisms.\nSuccessful exploitation of this security flaw enables unauthorized interception, eavesdropping, and potential manipulation of sensitive network traffic transiting the compromised communication channel.\nThe scope of affected systems includes Apple iOS and iPadOS versions prior to 26.6.1.\nThe primary risk implication is the complete compromise of data confidentiality and integrity for network sessions protected by IPSec, exposing sensitive communications to malicious observation.\nTo achieve exploitation, the attacker must possess specific attacker capabilities, specifically maintaining a privileged network position—such as an on-path or Man-in-the-Middle (MitM) positioning—to intercept and manipulate the cryptographic and state negotiation packets.\nNo specific preconditions or complex execution requirements are explicitly mandated beyond maintaining the requisite network adjacency or positioning to interact with the target device's IPSec session establishment.",
  "technicalDetails": "The underlying root cause of the vulnerability resides in flawed state management logic within the IPSec protocol implementation of the affected operating systems.\nState management vulnerabilities typically occur when a finite state machine fails to properly validate message sequences, transition states conditionally, or handle out-of-order or unexpected control packets during session establishment.\nIn this specific context, the vulnerable component fails to enforce strict state validation during the authentication phase of the IPSec security association negotiation.\nAn attacker leveraging a privileged network position initiates the attack flow by observing and intercepting the cryptographic handshake and state transition packets exchanged between the victim device and the designated VPN gateway or IPSec peer.\nDue to the deficient state management logic, the attacker can spoof, replay, or inject specific protocol control messages that improperly force the state machine to transition prematurely into an authenticated or established state without validating the requisite cryptographic credentials.\nBy manipulating the session state, the victim device treats an unauthenticated or maliciously controlled association as fully validated.\nThis bypasses the cryptographic mutual authentication checks normally enforced by IPSec.\nOnce the authentication phase is erroneously bypassed, the attacker successfully establishes a compromised security association.\nThe post-exploitation impact includes the interception of network traffic, allowing the attacker to capture plaintext payloads, perform traffic analysis, or execute further attacks against higher-layer protocols traversing the tunnel.\nThe affected versions are all instances of iOS and iPadOS prior to version 26.6.1.\nThe vulnerability requires network exposure via local or wide-area network interfaces where IPSec connections are negotiated, and it relies strictly on the attacker maintaining a privileged network position to manipulate the underlying protocol packets."
}