{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/windows-message-queuing/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":7.8,"id":"CVE-2026-33838"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Windows Message Queuing"],"_cs_severities":["high"],"_cs_tags":["privilege-escalation","windows"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eCVE-2026-33838 is a double free vulnerability residing within the Windows Message Queuing (MSMQ) service. This vulnerability enables an attacker, who already possesses local access to the system, to elevate their privileges. The vulnerability arises due to a flaw in how MSMQ handles memory allocation and deallocation, potentially leading to a double free condition. Successful exploitation allows the attacker to execute arbitrary code with elevated privileges, potentially gaining complete control over the affected system. Defenders should prioritize patching this vulnerability and implementing detection measures to identify potential exploitation attempts.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker gains initial local access to the target Windows system.\u003c/li\u003e\n\u003cli\u003eAttacker crafts a malicious MSMQ message designed to trigger the double free condition.\u003c/li\u003e\n\u003cli\u003eAttacker sends the crafted message to the MSMQ service.\u003c/li\u003e\n\u003cli\u003eMSMQ service processes the message, triggering the vulnerable code path.\u003c/li\u003e\n\u003cli\u003eThe vulnerable code path attempts to free a memory region that has already been freed.\u003c/li\u003e\n\u003cli\u003eThis double free corrupts the heap, potentially allowing the attacker to control memory allocation.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the heap corruption to overwrite critical system data or inject malicious code.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves arbitrary code execution with elevated privileges.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-33838 allows a local attacker to elevate their privileges to SYSTEM. This can lead to complete system compromise, allowing the attacker to install malware, steal sensitive data, or disrupt critical services. The vulnerability affects all systems where Windows Message Queuing is enabled. Given the prevalence of Windows systems, the potential impact is significant.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the Microsoft patch for CVE-2026-33838 as soon as possible.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Suspicious MSMQ Message Processing\u003c/code\u003e to identify potential exploitation attempts.\u003c/li\u003e\n\u003cli\u003eMonitor process creation events for suspicious activity originating from the \u003ccode\u003emqsvc.exe\u003c/code\u003e process related to Windows Message Queuing using the \u003ccode\u003eDetect MSMQ Service Spawning Suspicious Processes\u003c/code\u003e rule.\u003c/li\u003e\n\u003cli\u003eEnsure proper access controls are in place to limit who can interact with the MSMQ service.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-12T18:20:18Z","date_published":"2026-05-12T18:20:18Z","id":"https://feed.craftedsignal.io/briefs/2026-05-cve-2026-33838-msmq-double-free/","summary":"CVE-2026-33838 is a double free vulnerability in Windows Message Queuing that allows a locally authorized attacker to elevate privileges.","title":"CVE-2026-33838: Windows Message Queuing Double Free Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-05-cve-2026-33838-msmq-double-free/"}],"language":"en","title":"CraftedSignal Threat Feed — Windows Message Queuing","version":"https://jsonfeed.org/version/1.1"}