Description

A memory corruption issue was addressed with improved validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. Connecting to a malicious WebDAV server may result in code execution.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-09-14T21:17:21.810Z",
  "pubdate": "2026-09-14T21:17:21.810Z",
  "executiveSummary": "This vulnerability involves a memory corruption flaw within the WebDAV client implementation on Apple operating systems. The issue arises from improper validation of input during interactions with a WebDAV server, which can be exploited by a malicious actor to achieve arbitrary code execution. The vulnerability affects macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. Successful exploitation permits an unauthenticated remote attacker to gain control over the affected system by inducing the victim to connect to a compromised or malicious WebDAV server. Given that memory corruption can lead to reliable control flow hijacking, the risk implications are severe, potentially resulting in full system compromise, unauthorized data access, and the persistence of malicious payloads. Users are advised to upgrade to the specified patched versions immediately to remediate the underlying validation weakness.",
  "technicalDetails": "The vulnerability is characterized as a memory corruption issue stemming from inadequate input sanitization and boundary checking during the processing of WebDAV protocol communications. When a client establishes a connection to a WebDAV server, the underlying system framework processes various headers, responses, and XML-based payloads inherent to the protocol. Insufficient validation of these incoming data structures likely leads to buffer overflows, heap-based corruption, or use-after-free conditions within the network stack or related file system handlers.\nThe attack flow initiates when a user is enticed to mount a WebDAV share or navigate to a malicious WebDAV server endpoint. Once the connection is established, the server crafts malformed responses designed to trigger the identified memory corruption flaw during the parsing phase. By injecting a payload that exceeds allocated memory buffers or forces the system to reference a deallocated memory region, an attacker can manipulate the application's instruction pointer.\nSpecifically, the root cause is situated in the validation logic responsible for verifying the integrity and size of data structures transmitted over the WebDAV protocol. The lack of strict bounds checking allows an attacker to overwrite critical memory segments, such as return addresses or function pointers. By placing controlled data at specific memory offsets, the attacker can redirect the execution flow to a malicious payload—often referred to as shellcode or a ROP (Return-Oriented Programming) chain—which executes with the privileges of the user running the WebDAV client process.\nThis exploit is particularly dangerous because it does not require prior authentication or elevated privileges from the attacker; the requirement is merely that the victim performs a connection to the adversarial infrastructure. The post-exploitation impact includes the potential for arbitrary code execution, which facilitates unauthorized access to sensitive files, system monitoring, or the installation of further malicious software. The vulnerability remains present in versions prior to macOS Golden Gate 27, macOS Sequoia 15.8, and macOS Tahoe 26.7. Remediation requires updating the operating system to the patched versions where improved validation mechanisms have been implemented to correctly handle malformed or malicious WebDAV responses, effectively neutralizing the path for heap-based or buffer-related memory corruption."
}