{"cve":"CVE-2026-98995","nvd":{"published":"2026-10-23T13:17:21.660","modified":"2026-10-24T14:16:51.470","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnamespace: reset the old parent's ->overmount in mnt_change_mountpoint()\n\n__umount_mnt() resets ->overmount of the parent when it unmounts the\nmount that overmounts it. mnt_change_mountpoint() doesn't. It moves the\nmount to its new parent and leaves the old one pointing at it.\n\nFor a mount that is moved beneath in attach_recursive_mnt() that doesn't\nmatter. The new mount has already reset ->overmount of the old parent by\nthe time the old top mount is moved onto it.\n\nIt matters for reparent() though. propagate_umount() moves a surviving\novermount onto the first ancestor that isn't going to be unmounted. The\nmount it was taken from is unmounted immediately afterwards. If a file\ndescriptor keeps that unmounted mount alive ->overmount points at the\nmoved mount. That's a dangling pointer and UAF as the moved mount is\nunmounted and freed.\n\ndo_lock_mount() follows ->overmount from the target path under\nmount_lock. With a file descriptor on such a mount as the target of a\nmount beneath topmost_overmount() walks into the freed mount and\ndo_lock_mount() takes references on whatever it finds there.\n\nSo reset ->overmount of the old parent in mnt_change_mountpoint() the\nsame way __umount_mnt() does. A mount's ->overmount is then always a\nmount that is attached to it.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/08d575ee89393fd812dbdca7b5d7b4574cd5a564","https://git.kernel.org/stable/c/476ef286a7a5db8bda51325dc0c45887b4d99d9a","https://git.kernel.org/stable/c/5e0a1f2c753a79749bc2ead3ae2f2ede3941daa5"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:35.584907681+00:00"},"epss":{"cve":"CVE-2026-98995","score":0.00161,"percentile":0.0527,"date":"2026-10-25"},"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."]}