{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-42257/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"id":"CVE-2026-42257"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["net-imap"],"_cs_severities":["high"],"_cs_tags":["command-injection","imap","cve-2026-42257","execution","microsoft"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eCVE-2026-42257 is a command injection vulnerability affecting the net-imap component in certain Microsoft products. An attacker could exploit this vulnerability by injecting malicious commands into the \u0026ldquo;raw\u0026rdquo; arguments of multiple IMAP commands, potentially leading to arbitrary code execution on the server. This vulnerability allows unauthenticated attackers to execute code, posing a significant threat to the confidentiality, integrity, and availability of affected systems. Defenders should apply available patches as soon as possible and implement 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 identifies a vulnerable system running a Microsoft product using the affected net-imap component.\u003c/li\u003e\n\u003cli\u003eAttacker crafts a malicious IMAP command containing a command injection payload within the \u0026ldquo;raw\u0026rdquo; argument.\u003c/li\u003e\n\u003cli\u003eAttacker sends the crafted IMAP command to the vulnerable server.\u003c/li\u003e\n\u003cli\u003eThe net-imap component processes the command, improperly sanitizing the \u0026ldquo;raw\u0026rdquo; argument.\u003c/li\u003e\n\u003cli\u003eThe injected command is executed by the server\u0026rsquo;s operating system with the privileges of the IMAP service.\u003c/li\u003e\n\u003cli\u003eAttacker gains arbitrary code execution on the server.\u003c/li\u003e\n\u003cli\u003eAttacker may install malware, steal sensitive data, or pivot to other systems within the network.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-42257 allows an attacker to execute arbitrary commands on the compromised system. This can lead to complete system compromise, data theft, and disruption of services. The specific impact depends on the privileges of the IMAP service account, but could potentially allow an attacker to gain full control over the server. Given the widespread use of IMAP for email communication, this vulnerability poses a significant risk to organizations.\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-2026-42257 on systems using the affected net-imap component.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026ldquo;Detect CVE-2026-42257 Exploitation via Malicious IMAP Command\u0026rdquo; to detect exploitation attempts.\u003c/li\u003e\n\u003cli\u003eMonitor network traffic for suspicious IMAP commands containing shell metacharacters.\u003c/li\u003e\n\u003cli\u003eReview and harden the configuration of IMAP services to limit the impact of potential command injection vulnerabilities.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-11T07:34:44Z","date_published":"2026-05-11T07:34:44Z","id":"https://feed.craftedsignal.io/briefs/2026-05-net-imap-command-injection/","summary":"CVE-2026-42257 is a command injection vulnerability in net-imap that could allow an attacker to execute arbitrary commands on a vulnerable system.","title":"CVE-2026-42257 net-imap Command Injection Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-05-net-imap-command-injection/"}],"language":"en","title":"CraftedSignal Threat Feed — Cve-2026-42257","version":"https://jsonfeed.org/version/1.1"}