Description

Double free in Windows Kerberos allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.0",
  "pubDate": "2026-08-11T17:18:29.027Z",
  "pubdate": "2026-08-11T17:18:29.027Z",
  "executiveSummary": "This vulnerability involves a double free condition within the Windows Kerberos protocol implementation, specifically affecting Windows operating systems.\nThe primary impact of successful exploitation is local privilege escalation, allowing an authenticated adversary to elevate their execution context on the target host.\nThe affected product is Windows Kerberos, a core authentication component utilized across Windows domain environments and standalone systems.\nThe risk implications are severe, as an attacker who has already achieved initial access and local code execution can leverage this flaw to subvert security boundaries, attain elevated privileges, and potentially compromise the entire local system or domain assets.\nAttacker capabilities required for this vulnerability include local access to the target machine and authorization within the system environment to interact with the vulnerable Kerberos interfaces.\nExploitation requirements dictate that the attacker must execute malicious code locally to trigger the flawed memory management operations within the Kerberos subsystem.",
  "technicalDetails": "The root cause of the vulnerability is a double free memory management defect within the Windows Kerberos component. A double free occurs when the application attempts to deallocate the same memory buffer multiple times, leading to heap corruption.\nThe vulnerable component resides in the Windows Kerberos subsystem responsible for parsing and managing security ticket allocations, session contexts, and cryptographic buffers.\nAuthentication requirements dictate that the attacker must possess valid local execution privileges and interact with the vulnerable Kerberos APIs, meaning unauthenticated network-based exploitation is not the primary vector described.\nPrivilege requirements are initially low, as the attacker operates with standard user privileges locally, aiming to leverage the memory corruption flaw to escalate to higher integrity levels or SYSTEM privileges.\nNetwork exposure is localized, requiring local execution context rather than direct exposure to unauthenticated remote network vectors.\nThe exploitation method involves manipulating heap structures by forcing the Kerberos component to process specific sequences of requests that trigger the erroneous release of an already freed memory address.\nThe attack flow proceeds as follows: First, the local attacker interacts with the Windows Kerberos service via documented APIs or internal control codes. Second, the attacker induces a state where specific heap allocations are managed incorrectly, causing the application logic to issue a secondary free operation on a target memory pointer. Third, the resulting heap corruption destabilizes memory management control blocks. Fourth, the attacker crafts precise heap layouts to achieve arbitrary read or write primitives, or to execute arbitrary code within the context of the elevated service.\nPayload behavior during post-exploitation centers on subverting the security context, injecting malicious shellcode into privileged processes, and achieving local privilege escalation to compromise the underlying operating system fully."
}