{"id":"CVE-2026-98978","revision":null,"records":[{"revision":"9906618348aa4f0b8bdab51bad8f5294","observedAt":"2026-10-24T16:17:04.479+00:00","statement":{"source":"cve-program","id":"CVE-2026-98978","aliases":[],"title":"namespace: never expire a locked mount","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnamespace: never expire a locked mount\n\nLocked mounts are special. They protect the underlying files and\ndirectories from being revealed. do_umount() refuses to unmount locked\nmounts but shrink_submounts() doesn't.\n\nA shrinkable mount can become locked once the owner of a user namespace\nputs it beneath a locked mount with MOVE_MOUNT_BENEATH. The locked\nproperty now moves to the mount at the bottom making it possible to\nunmount the top mount.\n\nSo umount() of an unlocked ancestor now expires the bottom mount first\nand the covered directory is revealed:\n\n  move_mount(c -> x/hidden, MOVE_MOUNT_BENEATH) = 0\n  the cover after the lock moved:  umount2(x/hidden) = 0\n  the holder of the lock:          umount2(x/hidden) = EINVAL\n  the root of the copy, busy:      umount2(x) = EBUSY\n  reads x/hidden/secret: \"covered-by-root\"\n\nSo leave a locked mount alone as it dies together with its parent. A\nplain umount() of an unlocked mount with a locked one below it is EBUSY\nfrom now on. It's the same for any other locked child. A lazy umount\nstill takes the whole tree.\n\nmark_mounts_for_expiry() never sees a locked mount. lock_mnt_tree()\nleaves a mount on an expiry list alone and nothing else puts a locked\none on such a list. Add an assert for this.","state":0,"publishedAt":"2026-10-23T12:19:51.428+00:00","modifiedAt":"2026-10-24T14:09:47.444+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/namespace.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5ff9d8a65ce80efb509ce4e8051394e9ed2cd942\",\n                            \"lessThan\": \"6b8dc3713a76346d212abab46cbfc8d7070f534c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff9d8a65ce80efb509ce4e8051394e9ed2cd942\",\n                            \"lessThan\": \"d23265a12e4991ce7aedce670c0b6b598cadb644\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5ff9d8a65ce80efb509ce4e8051394e9ed2cd942\",\n                            \"lessThan\": \"f78ddcc872248c7aa1d7e904928441a0be4c6d5d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/namespace.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.12\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.12\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.57\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.11\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","score":8.4,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/6b8dc3713a76346d212abab46cbfc8d7070f534c","https://git.kernel.org/stable/c/d23265a12e4991ce7aedce670c0b6b598cadb644","https://git.kernel.org/stable/c/f78ddcc872248c7aa1d7e904928441a0be4c6d5d"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98978","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98978","identifiers":["CVE-2026-98978"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-10-26T00:46:57.9533087+00:00","complete":true,"records":1756,"lastAttemptAt":"2026-10-26T00:46:57.9533087+00:00","lastSuccessAt":"2026-10-26T00:46:58.1070069+00:00","error":null,"lastVerifiedAt":"2026-10-26T00:46:58.1070087+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-1a687ad2a0b90150aa7d97c9f39e63de695ae2db23e31ebc28df1492c461b23c-8739c76e681f900923b900c9df0ef75cf421d39cabb54650c4b9ad19b6a76d85","complete":true,"records":414048,"lastAttemptAt":"2026-10-26T00:46:56.7781981+00:00","lastSuccessAt":"2026-10-26T00:46:56.7731374+00:00","error":null,"lastVerifiedAt":"2026-10-26T00:46:56.7781981+00:00","snapshotPublishedAt":"2026-10-26T00:42:27+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-43321610382942b8ad8c85917eab1546","complete":false,"records":4735,"lastAttemptAt":"2026-10-26T00:47:02.6516296+00:00","lastSuccessAt":"2026-10-24T23:18:49.862+00:00","error":"InvalidDataException","lastVerifiedAt":"2026-10-24T23:18:49.862+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":4764,"expectedIdentifiers":13474},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-10-26T00:46:57.9533087+00:00","complete":true,"records":1093,"lastAttemptAt":"2026-10-26T00:46:57.9533087+00:00","lastSuccessAt":"2026-10-26T00:46:58.1082168+00:00","error":null,"lastVerifiedAt":"2026-10-26T00:46:58.1082172+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-204a3fb93a00487e8f7f36db01dc851d","complete":true,"records":13413,"lastAttemptAt":"2026-10-26T00:47:00.681998+00:00","lastSuccessAt":"2026-10-25T16:19:28.681+00:00","error":null,"lastVerifiedAt":"2026-10-25T16:19:28.681+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13474,"expectedIdentifiers":13474},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-2375a4e597279abf92e8747e140fe8da9d421877cd49cae3ac69a2cb78469b2c","complete":true,"records":9779,"lastAttemptAt":"2026-10-26T00:46:57.4114497+00:00","lastSuccessAt":"2026-10-24T13:19:53.1346702+00:00","error":null,"lastVerifiedAt":"2026-10-26T00:46:57.4114497+00:00","snapshotPublishedAt":"2026-10-24T03:03:12+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-16ad89dfea13ab9e9b0108e63a759d63bd4559cc68b58491107d62ee35bbbaf2","complete":true,"records":1965,"lastAttemptAt":"2026-10-26T00:46:56.9270949+00:00","lastSuccessAt":"2026-10-23T16:01:26.4487605+00:00","error":null,"lastVerifiedAt":"2026-10-26T00:46:56.9270949+00:00","snapshotPublishedAt":"2026-10-21T12:18:07+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-7da67a15aa6e56a0e3081a7646dc74d537e6ef974afc593c2b1794ed01970648","complete":true,"records":2969,"lastAttemptAt":"2026-10-26T00:46:57.8104847+00:00","lastSuccessAt":"2026-10-24T13:19:59.1145547+00:00","error":null,"lastVerifiedAt":"2026-10-26T00:46:57.8104847+00:00","snapshotPublishedAt":"2026-10-24T08:47:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-11236ada05a0588e51df37636716526867f73fb127392c49680b6f8561496a99","complete":true,"records":230781,"lastAttemptAt":"2026-10-26T00:46:57.3095832+00:00","lastSuccessAt":"2026-10-25T22:04:07.173333+00:00","error":null,"lastVerifiedAt":"2026-10-26T00:46:57.3095832+00:00","snapshotPublishedAt":"2026-10-25T21:33:06+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null}]}