{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/hyper-v/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":9.3,"id":"CVE-2026-40402"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Hyper-V"],"_cs_severities":["critical"],"_cs_tags":["privilege-escalation","use-after-free","hyper-v"],"_cs_type":"threat","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eCVE-2026-40402 is a critical use-after-free vulnerability affecting Windows Hyper-V. This flaw allows an attacker with local access to the system to escalate their privileges. The vulnerability stems from improper memory management within the Hyper-V component, potentially leading to exploitation where freed memory is accessed again. Successful exploitation could allow an attacker to gain elevated privileges on the system, potentially leading to complete system compromise. Defenders need to apply the patch released by Microsoft to mitigate this threat and prevent potential exploitation.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker gains initial local access to the target Windows system.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious Hyper-V request designed to trigger the use-after-free vulnerability.\u003c/li\u003e\n\u003cli\u003eThe crafted request interacts with the vulnerable Hyper-V component, leading to memory corruption.\u003c/li\u003e\n\u003cli\u003eThe Hyper-V service attempts to access previously freed memory.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the use-after-free condition to execute arbitrary code.\u003c/li\u003e\n\u003cli\u003eThe attacker\u0026rsquo;s code executes with elevated privileges within the Hyper-V environment.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages their elevated privileges within Hyper-V to compromise the host operating system.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves complete control over the system, enabling activities like data exfiltration, malware installation, or further lateral movement.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-40402 allows a local attacker to escalate privileges on the affected Windows system. This can lead to a complete system compromise, including unauthorized data access, modification, or destruction. Given the widespread use of Hyper-V in both enterprise and personal environments, this vulnerability poses a significant risk.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the security update provided by Microsoft to patch CVE-2026-40402 on all Windows systems running Hyper-V immediately.\u003c/li\u003e\n\u003cli\u003eEnable process creation logging to capture events related to potential exploitation attempts.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rules provided in this brief to your SIEM to detect potential exploitation attempts related to CVE-2026-40402.\u003c/li\u003e\n\u003cli\u003eMonitor for unexpected or unauthorized activity within the Hyper-V environment after patching.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-12T18:41:24Z","date_published":"2026-05-12T18:41:24Z","id":"https://feed.craftedsignal.io/briefs/2026-05-cve-2026-40402-hyper-v-uaf/","summary":"CVE-2026-40402 is a use-after-free vulnerability in Windows Hyper-V, enabling an unauthorized local attacker to escalate privileges.","title":"CVE-2026-40402 - Windows Hyper-V Use-After-Free Privilege Escalation","url":"https://feed.craftedsignal.io/briefs/2026-05-cve-2026-40402-hyper-v-uaf/"}],"language":"en","title":"CraftedSignal Threat Feed — Hyper-V","version":"https://jsonfeed.org/version/1.1"}