{"cve":"CVE-2026-43417","nvd":{"published":"2026-05-08T15:16:53.700","modified":"2026-06-17T10:49:33.523","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched/mmcid: Handle vfork()/CLONE_VM correctly\n\nMatthieu and Jiri reported stalls where a task endlessly loops in\nmm_get_cid() when scheduling in.\n\nIt turned out that the logic which handles vfork()'ed tasks is broken. It\nis invoked when the number of tasks associated to a process is smaller than\nthe number of MMCID users. It then walks the task list to find the\nvfork()'ed task, but accounts all the already processed tasks as well.\n\nIf that double processing brings the number of to be handled tasks to 0,\nthe walk stops and the vfork()'ed task's CID is not fixed up. As a\nconsequence a subsequent schedule in fails to acquire a (transitional) CID\nand the machine stalls.\n\nCure this by removing the accounting condition and make the fixup always\nwalk the full task list if it could not find the exact number of users in\nthe process' thread list.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/28b5a1395036d6c7a6c8034d85ad3d7d365f192c","https://git.kernel.org/stable/c/e6761cdce78a8919a537989afb6aaf6881469f83"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:33:55.586217763+00:00"},"epss":{"cve":"CVE-2026-43417","score":0.00107,"percentile":0.01155,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}