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A memory corruption vulnerability exists in Apple’s dyld (dynamic linker) component, which is responsible for loading and linking libraries and programs during runtime. The issue stems from improper state management during dyld’s handling of specific memory operations, allowing an attacker who has already achieved memory write capabilities to escalate that access into full arbitrary code execution. This flaw is particularly dangerous because it was exploited as part of a sophisticated exploit chain targeting iOS versions prior to iOS 26. The attack chain utilized two additional vulnerabilities (CVE-2025-14174 and CVE-2025-43529) to achieve initial access before triggering this memory corruption. The vulnerability affects the core operating system’s ability to maintain memory safety during dynamic linking processes, potentially allowing attackers to bypass security boundaries and execute malicious code with elevated privileges .
Platform: Apple Multiple Platforms
Version: Before 26.3
Vulnerability : Memory Corruption
Severity: Critical
Date: 11 Feb 2026
Prediction: Patches available
What Undercode Say:
Analytics:
This vulnerability (CVE-2026-20700) is a memory corruption issue in the `dyld` component. It was patched in February 2026 across watchOS 26.3, tvOS 26.3, macOS Tahoe 26.3, visionOS 26.3, iOS 26.3, and iPadOS 26.3. Apple credits Google Threat Analysis Group for the discovery, indicating state-sponsored exploitation. The flaw allows attackers with memory write capabilities to execute arbitrary code and was used in highly targeted attacks against specific individuals running iOS versions prior to iOS 26. The exploit chain also involved two previously patched vulnerabilities (CVE-2025-14174, an out-of-bounds read in Chrome/WebKit, and CVE-2025-43529, a use-after-free in WebKit) .
Bash Commands & Codes:
Check macOS version sw_vers Check if you are running a vulnerable version (anything below 26.3) system_profiler SPSoftwareDataType | grep "System Version" For iOS/iPadOS devices, check version via connected Mac ideviceinfo -k ProductVersion Command to manually check for updates on macOS softwareupdate --list Command to install all available updates on macOS sudo softwareupdate --install --all For iOS/iPadOS users, use CLI to check (requires libimobiledevice) ideviceinfo -k ProductVersion ideviceinfo -k BuildVersion Check if specific patches are applied (macOS) dyld version is tied to OS build, check build number sw_vers -buildVersion Check for CVE-2025-14174 related components (WebKit/Chrome) On macOS, check Safari version which includes WebKit /usr/libexec/PlistBuddy -c "Print :CFBundleShortVersionString" /Applications/Safari.app/Contents/Info.plist Monitor system logs for unusual dyld activity log show --predicate 'process == "dyld"' --last 1h Check for suspicious dynamic linker usage sudo dmesg | grep -i dyld
How Exploit:
- Initial Access: Attackers use CVE-2025-14174 (Chrome/WebKit out-of-bounds read) or CVE-2025-43529 (WebKit use-after-free) to achieve initial memory write capabilities through malicious web content .
- Trigger: With memory write primitive established, attackers trigger the state management flaw in dyld (CVE-2026-20700) .
- Corruption: Improper state handling allows attackers to corrupt critical memory structures used during program loading.
- Code Execution: The corruption redirects execution flow to attacker-controlled code, bypassing security protections like ASLR and code signing.
- Persistence: The arbitrary code executes with the privileges of the target process, allowing installation of spyware or backdoors without user awareness .
Protection from this CVE:
- Immediate Updates: Update all Apple devices to the latest versions:
– iOS/iPadOS: 26.3 or 18.7.5
– macOS: Tahoe 26.3, Sequoia 15.7.4, Sonoma 14.8.4
– watchOS: 26.3
– tvOS: 26.3
– visionOS: 26.3
– Safari: 26.3
2. Enable Auto-Updates:
- iOS/iPadOS: Settings > General > Software Update > Automatic Updates
- macOS: System Settings > General > Software Update > Automatic updates
- Restrict Web Content: Disable loading remote content in messages and emails until patched.
- Lockdown Mode: High-risk individuals should enable Apple’s Lockdown Mode to reduce attack surface.
- Avoid Untrusted Links: Do not open unsolicited links or attachments, especially from unknown senders .
Impact:
- Arbitrary Code Execution: Attackers can run malicious code with system privileges, completely compromising affected devices .
- Memory Corruption: The vulnerability directly corrupts kernel/dyld memory, bypassing fundamental security boundaries .
- Zero-Click Potential: When chained with the WebKit vulnerabilities, exploitation may require no user interaction beyond viewing malicious content.
- Surveillance Risk: Particularly dangerous for journalists, activists, and high-profile individuals targeted by sophisticated threat actors .
- Data Exposure: Successful exploitation leads to complete device compromise, exposing photos, messages, credentials, and sensitive data.
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Sources:
Reported By: www.cve.org
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