{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-26822","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-02-19T14:20:24.180Z","datePublished":"2024-04-17T09:43:49.221Z","dateUpdated":"2026-08-05T11:27:37.199Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:27:37.199Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: set correct id, uid and cruid for multiuser automounts\n\nWhen uid, gid and cruid are not specified, we need to dynamically\nset them into the filesystem context used for automounting otherwise\nthey'll end up reusing the values from the parent mount."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L","baseScore":8.7,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable code is reached by an ordinary path walk (`open`/`stat`/`chdir`) into a DFS junction or reparse point on a locally mounted SMB share, via `follow_automount()` → `cifs_d_automount()`. Delivery is a local syscall, not a network protocol message.\nAC:L - The attacker deterministically triggers the automount by traversing the path, and can plant the reparse-point/junction trigger themselves if they hold write access anywhere in the share; there is no race, no memory-layout dependency, and no reliance on victim state. `multiuser` plus DFS is the standard deployment for multi-user Linux clients in AD/Kerberos environments, not a rare configuration.\nPR:L - The attacker needs only an unprivileged local account with access to the existing `multiuser` CIFS mount; no capability, keyring privilege, or mount privilege is checked anywhere along `follow_automount()` → `cifs_do_automount()` → `fc_mount()`.\nUI:N - The attacker performs the triggering path traversal themselves and no other user has to act; the pre-existing `multiuser` mount is environment configuration established at boot/login, not victim interaction at exploit time.\nS:C - The wrong `cred_uid` makes the kernel request a Kerberos ticket for, and authenticate the submount as, a different principal (typically root or the machine account), so the impacted resources — server-side files and another principal's identity — are governed by the SMB server and KDC, a security authority distinct from the local kernel. This matches the repo's precedent of scoring cross-authority filesystem authorization bugs (e.g. CVE-2025-40362, ceph multifs MDS auth caps) as S:C.\nC:H - The unprivileged user obtains a tree connect and root/prefix-path queries against the DFS target under the mount owner's (typically root's) credentials, letting them read files and metadata across the DFS namespace they hold no rights to, with full control over which paths they target. The shared submount superblock and cache further break the per-user isolation `multiuser` exists to provide.\nI:H - The same borrowed high-privilege principal backs every operation issued over the submount's master tcon (including legacy `cifs_setattr`) and binds the whole submount namespace to another user's session, so data and metadata on the remote target can be modified under an identity the attacker does not own. Inode ownership on the submount is additionally attributed to the parent mount's uid/gid rather than the accessing user.\nA:L - There is no kernel crash, hang, or resource exhaustion, but automounts fail with -EACCES when the inherited `cred_uid`'s credential is unusable (the originally reported symptom), and superblock reuse keyed on the wrong uid can wedge users out — denying access to the DFS subtree for legitimate users, a limited availability loss."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/namespace.c"],"versions":[{"version":"c8117ac42303f7ae99bbe53e4952f7d147cca1fb","lessThan":"4a6e4c56721a3e6e2550b72ec56aab306c4607a7","status":"affected","versionType":"git"},{"version":"60e3318e3e900ba1ddfead937012b3432dfccc92","lessThan":"2ceba8ae1bd1f5589548cb722a5c583ca3a2dede","status":"affected","versionType":"git"},{"version":"9fd29a5bae6e8f94b410374099a6fddb253d2d5f","lessThan":"c2aa2718cda2d56b4a551cb40043e9abc9684626","status":"affected","versionType":"git"},{"version":"9fd29a5bae6e8f94b410374099a6fddb253d2d5f","lessThan":"7590ba9057c6d74c66f3b909a383ec47cd2f27fb","status":"affected","versionType":"git"},{"version":"9fd29a5bae6e8f94b410374099a6fddb253d2d5f","lessThan":"4508ec17357094e2075f334948393ddedbb75157","status":"affected","versionType":"git"},{"version":"5.15.124","lessThan":"5.15.201","status":"affected","versionType":"semver"},{"version":"6.1.54","lessThan":"6.1.164","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/namespace.c"],"versions":[{"version":"6.2","status":"affected"},{"version":"0","lessThan":"6.2","status":"unaffected","versionType":"semver"},{"version":"5.15.201","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.164","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.18","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.7.6","lessThanOrEqual":"6.7.*","status":"unaffected","versionType":"semver"},{"version":"6.8","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.124","versionEndExcluding":"5.15.201"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.54","versionEndExcluding":"6.1.164"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.7.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.8"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/4a6e4c56721a3e6e2550b72ec56aab306c4607a7"},{"url":"https://git.kernel.org/stable/c/2ceba8ae1bd1f5589548cb722a5c583ca3a2dede"},{"url":"https://git.kernel.org/stable/c/c2aa2718cda2d56b4a551cb40043e9abc9684626"},{"url":"https://git.kernel.org/stable/c/7590ba9057c6d74c66f3b909a383ec47cd2f27fb"},{"url":"https://git.kernel.org/stable/c/4508ec17357094e2075f334948393ddedbb75157"}],"title":"smb: client: set correct id, uid and cruid for multiuser automounts","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-26822","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-05-09T18:40:21.396618Z"}}}],"providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-06-04T17:48:41.629Z"}},{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-02T00:14:13.530Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/c2aa2718cda2d56b4a551cb40043e9abc9684626","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/7590ba9057c6d74c66f3b909a383ec47cd2f27fb","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/4508ec17357094e2075f334948393ddedbb75157","tags":["x_transferred"]}]}]}}