{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/udf/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"id":"CVE-2026-45991"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":[],"_cs_severities":["medium"],"_cs_tags":["udf","vulnerability","msft"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eCVE-2026-45991 describes a vulnerability in a Microsoft product related to Universal Disk Format (UDF) partition descriptor append bookkeeping. The specifics of the vulnerability are not detailed in the provided source. Due to the limited information available, the exact attack vector and affected products remain unclear. However, exploitation of this vulnerability could potentially allow an attacker to manipulate UDF partition descriptors, possibly leading to code execution or information disclosure. This vulnerability warrants further investigation and patching by affected users once Microsoft releases more details.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003cp\u003eDue to the lack of specifics regarding the vulnerability, a detailed attack chain cannot be constructed. However, a general attack chain based on similar vulnerabilities is outlined below as a hypothetical scenario:\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker crafts a malicious UDF image or file system.\u003c/li\u003e\n\u003cli\u003eThe victim\u0026rsquo;s system attempts to mount or access the crafted UDF image/file system.\u003c/li\u003e\n\u003cli\u003eThe UDF driver parses the partition descriptor.\u003c/li\u003e\n\u003cli\u003eDue to incorrect bookkeeping, the driver fails to properly validate the append operation.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the improper append bookkeeping to overwrite critical data structures.\u003c/li\u003e\n\u003cli\u003eThis leads to arbitrary code execution within the context of the UDF driver.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-45991 could potentially allow an attacker to achieve arbitrary code execution on a vulnerable system. This could lead to complete system compromise, data exfiltration, or denial of service. The specific impact will depend on the privileges of the account running the UDF driver and the nature of the code injected by the attacker.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor for attempts to mount or access unusual UDF images, using the rule \u003ccode\u003eDetect Suspicious UDF Image Mount\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eImplement network egress filtering to block connections originating from processes that handle UDF images, as detected by the rule \u003ccode\u003eDetect Outbound Network Connection from UDF Handling Process\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rules in this brief to your SIEM and tune for your environment.\u003c/li\u003e\n\u003cli\u003eApply the patch provided by Microsoft for CVE-2026-45991 as soon as it is released to remediate the vulnerability.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-28T07:21:33Z","date_published":"2026-05-28T07:21:33Z","id":"https://feed.craftedsignal.io/briefs/2026-05-cve-2026-45991/","summary":"CVE-2026-45991 is a security vulnerability affecting a Microsoft product, related to UDF partition descriptor append bookkeeping.","title":"CVE-2026-45991 UDF Partition Descriptor Append Bookkeeping Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-05-cve-2026-45991/"}],"language":"en","title":"CraftedSignal Threat Feed — Udf","version":"https://jsonfeed.org/version/1.1"}