{"id":"CVE-2026-74730","state":"PUBLISHED","title":"NFS: Pin the 'struct nfs_server' during a FREE_STATEID call","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Pin the 'struct nfs_server' during a FREE_STATEID call\n\nDan Aloni reports that he was able to hit a use-after-free bug if a\nFREE_STATEID operation gets delayed for whatever reason. Fix this by\nbumping the refcount of the 'struct nfs_server' object for the duration\nof the FREE_STATEID so it doesn't get cleaned up from underneath us\nwhile operations are still in flight.","publishedAt":"2026-08-22T15:33:19.659Z","updatedAt":"2026-10-16T19:16:12.405Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"ed2f92ce2fc48463c41e0e540b9a3454889e8af8","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"d858ab09e787106432d4d9830bad9dfedf02f890","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"af62f1af182d33a0de38308c012841885d8ab92e","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"caee6a68ffaa5016dfc01cd0b3dc1896a32e3abd","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"ed1161ab6239761958b38d5667225634fc2be894","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"d71dfffa512e71b166a889484e4c3b148a9a3af2","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"80ed3d762628b36c9e4b22fac7c65b72ef3b13dd","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"cf616096a0f3a2b60f7d68b6b39674a6867ded9c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfs/nfs4proc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.10","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.152","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.104","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.45","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfs/nfs4proc.c"]}],"references":["https://git.kernel.org/stable/c/ed2f92ce2fc48463c41e0e540b9a3454889e8af8","https://git.kernel.org/stable/c/d858ab09e787106432d4d9830bad9dfedf02f890","https://git.kernel.org/stable/c/af62f1af182d33a0de38308c012841885d8ab92e","https://git.kernel.org/stable/c/caee6a68ffaa5016dfc01cd0b3dc1896a32e3abd","https://git.kernel.org/stable/c/ed1161ab6239761958b38d5667225634fc2be894","https://git.kernel.org/stable/c/d71dfffa512e71b166a889484e4c3b148a9a3af2","https://git.kernel.org/stable/c/80ed3d762628b36c9e4b22fac7c65b72ef3b13dd","https://git.kernel.org/stable/c/cf616096a0f3a2b60f7d68b6b39674a6867ded9c"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74730.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74730","state":"PUBLISHED","datePublished":"2026-08-22T15:33:19.659Z","dateUpdated":"2026-10-16T19:16:12.405Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.930Z"},"containers":{"cna":{"title":"NFS: Pin the 'struct nfs_server' during a FREE_STATEID call","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Pin the 'struct nfs_server' during a FREE_STATEID call\n\nDan Aloni reports that he was able to hit a use-after-free bug if a\nFREE_STATEID operation gets delayed for whatever reason. Fix this by\nbumping the refcount of the 'struct nfs_server' object for the duration\nof the FREE_STATEID so it doesn't get cleaned up from underneath us\nwhile operations are still in flight."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"ed2f92ce2fc48463c41e0e540b9a3454889e8af8","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"d858ab09e787106432d4d9830bad9dfedf02f890","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"af62f1af182d33a0de38308c012841885d8ab92e","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"caee6a68ffaa5016dfc01cd0b3dc1896a32e3abd","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"ed1161ab6239761958b38d5667225634fc2be894","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"d71dfffa512e71b166a889484e4c3b148a9a3af2","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"80ed3d762628b36c9e4b22fac7c65b72ef3b13dd","versionType":"git"},{"version":"7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009","status":"affected","lessThan":"cf616096a0f3a2b60f7d68b6b39674a6867ded9c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfs/nfs4proc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.10","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.152","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.104","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.45","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfs/nfs4proc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ed2f92ce2fc48463c41e0e540b9a3454889e8af8"},{"url":"https://git.kernel.org/stable/c/d858ab09e787106432d4d9830bad9dfedf02f890"},{"url":"https://git.kernel.org/stable/c/af62f1af182d33a0de38308c012841885d8ab92e"},{"url":"https://git.kernel.org/stable/c/caee6a68ffaa5016dfc01cd0b3dc1896a32e3abd"},{"url":"https://git.kernel.org/stable/c/ed1161ab6239761958b38d5667225634fc2be894"},{"url":"https://git.kernel.org/stable/c/d71dfffa512e71b166a889484e4c3b148a9a3af2"},{"url":"https://git.kernel.org/stable/c/80ed3d762628b36c9e4b22fac7c65b72ef3b13dd"},{"url":"https://git.kernel.org/stable/c/cf616096a0f3a2b60f7d68b6b39674a6867ded9c"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The bug is in the NFSv4 client FREE_STATEID path: nfs41_free_stateid_prepare/done/release use a freed struct nfs_server while handling async RPC completions driven by NFSv4 replies from the mounted server and by server-initiated CB_RECALL/CB_RECALLANY callbacks on the NFS backchannel.\nAC:L - The attacker controls both sides of the race: they provoke FREE_STATEID via revocation responses or callbacks, keep it in flight with NFS4ERR_DELAY, and time nfs_server teardown via user-mount umount, automount idle expiry, or the concurrent stateid cleanup that runs during umount itself.\nPR:N - A malicious or compromised NFSv4 server needs no account or elevated capability on the victim client once an NFSv4.1+ mount exists; FREE_STATEID is issued automatically during server-driven stateid revocation handling without any client-side privileges at exploit time.\nUI:N - After an NFS mount exists (boot-time, autofs, or Kubernetes volumes are common), no further victim action is needed: the attacker drives recall/revocation on the wire and mount teardown follows from automated autofs expiry or attacker-controlled umount on a user-mounted export.\nS:U - The use-after-free corrupts kernel heap within the NFS client on the same host; it is a standard kernel memory-safety bug, not a VM escape, container breakout, or IOMMU/DMA boundary crossing.\nC:H - Freed struct nfs_server objects are kmalloc'd and callbacks dereference nfs_client, rpc_clnt, and super_block fields after nfs_free_server/call_rcu, giving a classic UAF read primitive over attacker-influenced heap contents including function pointers.\nI:H - UAF on struct nfs_server exposes destroy hooks, RPC client handles, and client/session state pointers that an attacker can reschedule via heap grooming, yielding write and control-flow primitives typical of NFS client heap corruption bugs.\nA:H - Use of a freed nfs_server in RPC prepare/done/release paths causes kernel oops or panic; Dan Aloni demonstrated reliable reproduction, and UAFs in this path crash hosts even when not fully weaponized."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-25T05:42:09.527Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.6.152"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.12.104"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74730","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T19:15:50.650757Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:16:12.405Z"}}]}}}