CVE-2026-50216 in Guardicore Platform Agent
Summary
by MITRE • 10/14/2026
An integer underflow exists in the DNS proxy component of the macOS NetworkExtension system extension shipped with Akamai Guardicore Platform Agent (GPA) for macOS, whereby if a UDP datagram shorter than 96 bytes that begins with a specific value is received, a subsequent size computation underflows to a near-SIZE_MAX value, causing an allocation failure and uncaught Objective-C exception that aborts the root system extension.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified in the Akamai Guardicore Platform Agent for macOS involves a critical integer underflow within the DNS proxy component of the NetworkExtension system extension. This flaw is triggered specifically when the application processes UDP datagrams that are shorter than 96 bytes and begin with a specific header value. The core technical issue stems from an arithmetic operation where a smaller size field or offset is subtracted from a larger constant, resulting in a negative integer result. Because this calculation likely involves unsigned integer types common in low-level network processing code, the underflow wraps around to produce a near-SIZE_MAX value, which represents the maximum possible addressable memory space on 64-bit systems.
This erroneous size computation directly leads to an allocation failure within the system extension's memory management routines. The application attempts to allocate a buffer of this impossibly large size, which inevitably fails due to insufficient available memory or operating system restrictions. However, rather than gracefully handling this allocation error through standard exception handling mechanisms, the code proceeds in a manner that triggers an uncaught Objective-C exception. In the context of macOS system extensions, particularly those running with elevated privileges as part of network security infrastructure like Guardicore GPA, such exceptions are not merely application-level errors but critical stability failures.
The operational impact of this vulnerability is severe, resulting in the immediate termination or abort of the root system extension. Since the DNS proxy component is integral to the agent's ability to monitor and control network traffic for threat detection and policy enforcement, its abrupt cessation effectively disables a key layer of security protection on the affected macOS device. An attacker who can craft and send these specific malformed UDP packets could induce this denial-of-service condition repeatedly, causing intermittent or persistent outages in DNS resolution and potentially disrupting other dependent services that rely on the stability of the NetworkExtension framework. This aligns with CWE-191 (Integer Underflow) as the root cause classification and falls under ATT&CK technique T1499 (Endpoint Denial of Service), specifically targeting system availability through resource exhaustion or crash induction via malformed input.
Mitigation strategies must focus on both immediate remediation and long-term defensive coding practices. The primary solution is to apply the vendor-provided software update that patches this integer underflow by implementing proper bounds checking before performing arithmetic operations on packet sizes. Developers should ensure that all size calculations involving user-controlled or network-derived data are validated against minimum thresholds, such as verifying that a datagram meets the expected 96-byte minimum length prior to any subtraction or allocation logic. Additionally, integrating robust error handling for memory allocation failures is essential; instead of allowing uncaught exceptions to crash the process, the application should log the anomaly and safely terminate specific operations without compromising the entire extension's lifecycle. Regular static analysis scanning for integer overflow and underflow vulnerabilities can further prevent similar issues in future code releases.