CVE-2026-112518 in iOS
Summary
by MITRE • 10/26/2026
An issue with signature validation was addressed with improved checks. This issue is fixed in iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, tvOS 27.2, visionOS 27.2, watchOS 27.2. An attacker in a privileged network position may be able to impersonate a Kerberos KDC.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/27/2026
The vulnerability described involves a critical flaw in the signature validation mechanisms within Apple's operating systems, specifically affecting iOS, iPadOS, macOS Golden Gate, tvOS, visionOS, and watchOS versions prior to 27.2. The core technical issue lies in insufficient verification of cryptographic signatures during authentication processes, which undermines the integrity guarantees provided by secure communication protocols. By addressing this with improved checks, Apple has patched a weakness that allowed for potential manipulation or bypassing of standard security controls designed to ensure data authenticity and origin validation.
This flaw is particularly significant because it impacts Kerberos implementations across these platforms. Kerberos is a network authentication protocol that uses ticket-granting tickets to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner. The vulnerability enables an attacker positioned within the same privileged network segment to exploit this validation gap. Specifically, such an attacker can impersonate a Key Distribution Center (KDC), which is the central authority responsible for issuing tickets and authenticating users and services within a Kerberos realm.
The operational impact of this vulnerability is severe in enterprise or complex network environments where Kerberos is heavily utilized for single sign-on and service authentication. An adversary capable of performing a man-in-the-middle attack or possessing sufficient access to intercept and manipulate network traffic can exploit the weak signature validation to present forged tickets as if they originated from a legitimate KDC. This allows the attacker to authenticate as any user or service within the domain, effectively gaining unauthorized access to sensitive resources, data stores, and administrative functions without detection by standard authentication logs that rely on ticket validity rather than deep cryptographic verification of every step in the handshake process.
From a classification perspective, this vulnerability aligns with CWE-347, which describes Improper Verification of Cryptographic Signature. This weakness occurs when software does not properly verify digital signatures before trusting data or executing code based on those signatures. Furthermore, within the MITRE ATT&CK framework, this exploit scenario maps to T1558.003, Steal or Forge Kerberos Tickets: Golden Ticket. A golden ticket attack involves forging a Ticket Granting Ticket (TGT) using the KRBTGT account's NTLM hash. While traditional golden tickets rely on stealing keys, vulnerabilities in signature validation can allow for more dynamic forgery or bypass of integrity checks that would normally detect such anomalies, thereby facilitating persistent unauthorized access and lateral movement within an Active Directory environment.
Mitigation strategies primarily involve applying the provided software updates to iOS 27.2, iPadOS 27.2, macOS Golden Gate 27.2, tvOS 27.2, visionOS 27.2, and watchOS 27.2 immediately upon availability for affected devices. For network administrators managing these endpoints, it is crucial to ensure that all client systems are patched to prevent them from accepting forged tickets or failing to detect malicious KDC impersonation attempts. Additionally, organizations should enforce strict network segmentation policies to limit the ability of potential attackers to position themselves in privileged network positions where they could intercept Kerberos traffic. Implementing additional monitoring for anomalous authentication patterns and ensuring that critical services utilize mutual authentication can further reduce the risk posed by this class of vulnerabilities until all endpoints are fully updated.