CVE-2026-43813 in iOS
Summary
by MITRE • 07/28/2026
A validation issue was addressed with improved input sanitization. This issue is fixed in iOS 26.6 and iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, watchOS 26.6. A maliciously crafted app may be able to bypass code signing enforcement.
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Analysis
by VulDB Data Team • 07/28/2026
This vulnerability represents a critical code signing enforcement bypass issue that undermines the fundamental security mechanisms protecting Apple's ecosystem. The problem stems from inadequate input validation during the code signing verification process, allowing malicious applications to potentially circumvent the system's integrity checks. Such flaws directly compromise the trust model that Apple maintains across all its platforms including iOS, iPadOS, macOS, tvOS, visionOS, and watchOS. The vulnerability demonstrates a failure in the input sanitization controls that should prevent unauthorized code execution and maintain the security boundaries between legitimate applications and malicious payloads.
The technical implementation of this flaw likely involves insufficient validation of digital signatures or certificate chains during the code signing process. Attackers could craft specially designed applications that exploit gaps in the input sanitization routines, potentially enabling them to inject malicious code that appears to originate from legitimate sources. This type of vulnerability falls under CWE-20, which addresses improper input validation issues, and represents a direct threat to the software supply chain security model. The flaw specifically targets the code signing enforcement mechanisms that are crucial for maintaining system integrity and preventing unauthorized modifications to applications.
The operational impact of this vulnerability extends beyond simple bypass scenarios as it creates potential pathways for persistent malware deployment across multiple Apple platforms. An attacker who successfully exploits this vulnerability could deploy malicious applications that evade detection by standard security mechanisms, potentially leading to full system compromise or data exfiltration. The cross-platform nature of the affected systems increases the attack surface significantly, as a single exploit could potentially affect all Apple devices running the vulnerable versions. This vulnerability aligns with ATT&CK technique T1553.004 related to code signing policy modification and represents a serious threat to enterprise security environments where Apple devices are prevalent.
The remediation strategy for this vulnerability involves implementing robust input sanitization mechanisms that validate all aspects of code signing certificates, digital signatures, and application metadata before granting execution privileges. Apple's release of updates for iOS 26.6, iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, and watchOS 26.6 demonstrates the company's recognition of this threat level. Organizations should prioritize immediate deployment of these updates across all affected systems and implement additional monitoring for suspicious code signing activities. Security teams should also review their existing code signing policies and consider implementing additional verification layers beyond the standard operating system protections to maintain defense in depth. The vulnerability serves as a reminder of the critical importance of maintaining strong input validation controls in security-sensitive contexts, particularly those involving cryptographic operations and digital signatures that form the backbone of modern application security models.