{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/remote-desktop/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":7.8,"id":"CVE-2026-40398"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Remote Desktop"],"_cs_severities":["high"],"_cs_tags":["privilege-escalation","heap-buffer-overflow","rdp"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eCVE-2026-40398 is a heap-based buffer overflow vulnerability affecting Windows Remote Desktop. An attacker with local access and valid credentials can exploit this vulnerability to escalate their privileges on the system. The vulnerability stems from improper memory management within the Remote Desktop service, potentially allowing an attacker to overwrite critical system data and execute arbitrary code with elevated privileges. Successful exploitation grants the attacker increased control over the compromised system. The CVE was published on 2026-05-12 and defenders need to investigate and apply appropriate patches from Microsoft to 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 access to a Windows system with Remote Desktop enabled, either through valid credentials or by exploiting a separate vulnerability.\u003c/li\u003e\n\u003cli\u003eThe attacker authenticates to the Remote Desktop service.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious payload designed to trigger the heap-based buffer overflow.\u003c/li\u003e\n\u003cli\u003eThe malicious payload is sent to the Remote Desktop service during a normal RDP session or via a malformed request.\u003c/li\u003e\n\u003cli\u003eThe Remote Desktop service improperly handles the payload, leading to a buffer overflow in the heap.\u003c/li\u003e\n\u003cli\u003eThe attacker overwrites adjacent memory regions with attacker-controlled data, including critical system structures.\u003c/li\u003e\n\u003cli\u003eThe attacker gains the ability to execute arbitrary code with elevated privileges (SYSTEM).\u003c/li\u003e\n\u003cli\u003eThe attacker can now perform actions such as installing software, modifying data, and creating new accounts with full administrative rights.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-40398 leads to local privilege escalation, granting an attacker complete control over the affected Windows system. This could allow the attacker to steal sensitive data, install malware, or use the compromised system as a pivot point to attack other systems on the network. Systems running vulnerable versions of Windows Remote Desktop are susceptible. Given the ubiquity of Remote Desktop, this vulnerability poses a significant risk to organizations that rely on RDP for remote administration and user access.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the security updates provided by Microsoft to patch CVE-2026-40398 as soon as possible, referencing the Microsoft advisory URL in the references section.\u003c/li\u003e\n\u003cli\u003eMonitor process creation events for unusual processes spawned by the \u003ccode\u003etermsrv.exe\u003c/code\u003e (Remote Desktop Service) process, using the provided Sigma rule.\u003c/li\u003e\n\u003cli\u003eImplement network segmentation to limit the blast radius of a potential compromise, reducing the impact of successful privilege escalation.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-12T18:46:20Z","date_published":"2026-05-12T18:46:20Z","id":"https://feed.craftedsignal.io/briefs/2026-05-cve-2026-40398-rdp-privesc/","summary":"CVE-2026-40398 is a heap-based buffer overflow vulnerability in Windows Remote Desktop that allows an authorized attacker to elevate privileges locally.","title":"CVE-2026-40398: Windows Remote Desktop Heap-Based Buffer Overflow Privilege Escalation","url":"https://feed.craftedsignal.io/briefs/2026-05-cve-2026-40398-rdp-privesc/"}],"language":"en","title":"CraftedSignal Threat Feed — Remote Desktop","version":"https://jsonfeed.org/version/1.1"}