{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-33099/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":7,"id":"CVE-2026-33099"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["cve-2026-33099","use-after-free","privilege-escalation","windows"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eCVE-2026-33099 is a use-after-free vulnerability affecting the Windows Ancillary Function Driver for WinSock. This vulnerability allows an attacker with local access and valid credentials to escalate their privileges on the affected system. Successful exploitation could allow the attacker to execute arbitrary code with elevated permissions, potentially leading to full system compromise. While the specific attack vector is not detailed in the provided source, the vulnerability lies within a core networking component, suggesting avenues for exploitation via crafted network requests or local API calls related to WinSock functions. The vulnerability was published on April 14, 2026. Defenders should prioritize patching systems to prevent potential exploitation.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker gains initial access to the target Windows system with valid user credentials (e.g., via compromised credentials or physical access).\u003c/li\u003e\n\u003cli\u003eThe attacker executes a specially crafted application or script.\u003c/li\u003e\n\u003cli\u003eThe application interacts with the Windows Ancillary Function Driver (AFD.sys) for WinSock.\u003c/li\u003e\n\u003cli\u003eThe crafted interaction triggers the use-after-free vulnerability within AFD.sys.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the use-after-free condition to corrupt memory.\u003c/li\u003e\n\u003cli\u003eThe attacker overwrites critical system structures in memory with controlled data.\u003c/li\u003e\n\u003cli\u003eThe memory corruption allows the attacker to inject malicious code into a privileged process.\u003c/li\u003e\n\u003cli\u003eThe injected code executes with elevated privileges, granting the attacker increased access to the system.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-33099 allows a local attacker to elevate privileges on a Windows system. This could lead to unauthorized access to sensitive data, installation of malware, or complete system compromise. The vulnerability affects a core Windows networking component, making a wide range of systems potentially vulnerable. While the exact number of affected systems is unknown, the potential impact is significant due to the widespread use of Windows.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the security update released by Microsoft to patch CVE-2026-33099 on all affected Windows systems. Refer to the Microsoft Security Response Center advisory for CVE-2026-33099 for the appropriate patch.\u003c/li\u003e\n\u003cli\u003eEnable Sysmon process creation logging to enhance visibility into process execution and potential exploitation attempts.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rules provided below to detect potential exploitation attempts related to CVE-2026-33099.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-15T12:00:00Z","date_published":"2026-04-15T12:00:00Z","id":"/briefs/2026-04-cve-2026-33099/","summary":"A use-after-free vulnerability, CVE-2026-33099, in the Windows Ancillary Function Driver for WinSock, enables a locally authenticated attacker to elevate privileges on the system.","title":"CVE-2026-33099: Windows WinSock Use-After-Free Privilege Escalation","url":"https://feed.craftedsignal.io/briefs/2026-04-cve-2026-33099/"}],"language":"en","title":"CraftedSignal Threat Feed — Cve-2026-33099","version":"https://jsonfeed.org/version/1.1"}