CVE-2026-74730 (GCVE-0-2026-74730)
Vulnerability from cvelistv5
Published
2026-08-22 15:33
Modified
2026-08-25 05:42
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
NFS: Pin the 'struct nfs_server' during a FREE_STATEID call
Dan Aloni reports that he was able to hit a use-after-free bug if a
FREE_STATEID operation gets delayed for whatever reason. Fix this by
bumping the refcount of the 'struct nfs_server' object for the duration
of the FREE_STATEID so it doesn't get cleaned up from underneath us
while operations are still in flight.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009 Version: 7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009 Version: 7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009 Version: 7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009 Version: 7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009 Version: 7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009 Version: 7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009 Version: 7c1d5fae4a87d3cf3e9ffd68bcdbaf6529013009 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/nfs/nfs4proc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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},
{
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"programFiles": [
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.10"
},
{
"lessThan": "3.10",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.152",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.104",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.45",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.9",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.265",
"versionStartIncluding": "3.10",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.216",
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{
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{
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Pin the \u0027struct nfs_server\u0027 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 \u0027struct nfs_server\u0027 object for the duration\nof the FREE_STATEID so it doesn\u0027t get cleaned up from underneath us\nwhile operations are still in flight."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"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\u0027d 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": {
"dateUpdated": "2026-08-25T05:42:09.527Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"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"
}
],
"title": "NFS: Pin the \u0027struct nfs_server\u0027 during a FREE_STATEID call",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74730",
"datePublished": "2026-08-22T15:33:19.659Z",
"dateReserved": "2026-08-15T05:44:03.930Z",
"dateUpdated": "2026-08-25T05:42:09.527Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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