CVE-2026-20700

Apple Multiple Products Buffer Overflow Exploitation (CVE-2026-20700)

Detects exploitation attempts and post-exploitation activity related to CVE-2026-20700, a buffer overflow vulnerability (CWE-119) affecting multiple Apple products. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild. Buffer overflow exploitation against Apple platforms may result in arbitrary code execution, privilege escalation, or sandbox escape.

Vulnerability Intelligence

KEV — Known Exploited

What is CVE-2026-20700 Apple Multiple Products Buffer Overflow Exploitation (CVE-2026-20700)?

Apple Multiple Products Buffer Overflow Exploitation (CVE-2026-20700) (CVE-2026-20700) maps to the Initial Access and Execution and Privilege Escalation tactics — the adversary is trying to get into your network in MITRE ATT&CK.

This page provides production-ready detection logic for Apple Multiple Products Buffer Overflow Exploitation (CVE-2026-20700), covering the data sources and telemetry it touches: Microsoft Defender for Endpoint, Microsoft Sentinel. The queries below are rated high severity at medium confidence, and ship for 7 SIEM platforms — KQL, SPL, Elastic, QRadar, Sumo, YARA-L, LogScale.

MITRE ATT&CK

Tactic
Initial Access Execution Privilege Escalation
Microsoft Sentinel / Defender
kusto
let timeframe = 24h;
DeviceEvents
| where Timestamp > ago(timeframe)
| where DeviceType == "AppleDevice" or OSPlatform has_any ("macOS", "iOS", "iPadOS")
| where ActionType in ("ExploitGuardNonMicrosoftSignedBlocked", "MemoryAllocationViolationBlocked", "ProcessInjection", "ShellcodeExecution")
| project Timestamp, DeviceName, AccountName, ActionType, FileName, ProcessCommandLine, RemoteIP, RemotePort
| union (
    DeviceProcessEvents
    | where Timestamp > ago(timeframe)
    | where OSPlatform has_any ("macOS", "iOS", "iPadOS")
    | where ProcessCommandLine has_any ("heap spray", "rop chain") or (InitiatingProcessFileName in~ ("Safari", "WebKit", "com.apple.webkit", "MobileSafari") and FileName in~ ("sh", "bash", "zsh", "python", "python3", "osascript", "launchctl"))
    | project Timestamp, DeviceName, AccountName, ActionType="SuspiciousChildProcess", FileName, ProcessCommandLine, RemoteIP="", RemotePort=0
)
| extend Severity = "High"
| extend CVE = "CVE-2026-20700"
| order by Timestamp desc

Detects memory violation events and suspicious process spawning from Apple platform browser or webkit processes that may indicate CVE-2026-20700 exploitation. Unions device exploit guard events with suspicious child process creation from Apple browser components.

high severity medium confidence

Data Sources

Microsoft Defender for Endpoint Microsoft Sentinel

Required Tables

DeviceEvents DeviceProcessEvents

False Positives

  • Legitimate developer tools or debuggers triggering memory instrumentation alerts on macOS
  • Security testing tools or penetration testing activities on Apple devices in managed environments
  • Legitimate automation scripts launched by browser extensions with elevated privileges
  • Memory profiling or performance analysis tools generating similar telemetry

Sigma rule & cross-platform mapping

The detection logic for Apple Multiple Products Buffer Overflow Exploitation (CVE-2026-20700) (CVE-2026-20700) above is provided in a vendor-neutral form so you can deploy it on any SIEM. The same logic is shipped here as native KQL (Microsoft Sentinel / Defender), SPL (Splunk), Elastic (Elastic Security (EQL)), QRadar (IBM QRadar (AQL)), Sumo (Sumo Logic CSE), YARA-L (Google Chronicle / SecOps), LogScale (CrowdStrike LogScale (CQL)) queries. In Sigma terms, this detection targets the following logsource:

logsource:
  category: process_creation
  product: windows

Browse the community-maintained Sigma rules for this technique:


Testing Methodology

Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.

  1. Test 1Simulate WebKit Child Process Spawn (macOS)

    Expected signal: EDR should log process creation event with parent process name matching 'com.apple.WebKit.WebContent' spawning 'bash' with shell commands. Network telemetry should show no external connections in this baseline test.

  2. Test 2Simulate Post-Exploitation Persistence via LaunchAgent (macOS)

    Expected signal: File creation event in ~/Library/LaunchAgents/ with a plist filename mimicking Apple system components. EDR should log the file write and potentially the LaunchAgent registration.

  3. Test 3Simulate Exploit Attempt Network Callback (macOS)

    Expected signal: Network connection attempt from curl process with unusual User-Agent string. In production scenario, this would be replaced with the WebKit process making the network connection directly.

  4. Test 4Heap Spray Pattern Simulation via Python (macOS/Linux)

    Expected signal: Python process allocating large contiguous memory blocks in rapid succession. Memory allocation anomaly detection in EDR should generate telemetry showing large heap allocations.

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