CVE-2026-68178 (GCVE-0-2026-68178)
Vulnerability from cvelistv5 – Published: 2026-08-10 11:59 – Updated: 2026-08-17 05:00
VLAI
EPSS
VEX
Title
misc: nsm: pin the module while the device is open
Summary
In the Linux kernel, the following vulnerability has been resolved:
misc: nsm: pin the module while the device is open
misc_open() installs a misc driver's file operations with fops_get(),
which pins file_operations::owner before replacing the file's f_op. The
NSM misc device leaves nsm_dev_fops.owner unset, so opening /dev/nsm does
not take a module reference on the nsm driver.
If the driver is built as a module, an open file descriptor can therefore
survive rmmod of the module that provides its ioctl callbacks. A later
ioctl through that descriptor can call into unloaded module text.
Set nsm_dev_fops.owner to THIS_MODULE so the misc core holds the module
while any /dev/nsm file descriptor is open, matching the lifetime
expectation for the installed file operations.
Severity
7.8 (High)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
b9873755a6c8ccfce79094c4dce9efa3ecb1a749 , < 1996639f824ce9468395cdb7bcb8f467fa787e77
(git)
Affected: b9873755a6c8ccfce79094c4dce9efa3ecb1a749 , < 1da310b94504d42001e9c32c43c5dc105b777e5f (git) Affected: b9873755a6c8ccfce79094c4dce9efa3ecb1a749 , < 9e9a82d00c3d10129fc310a7547b24a679d5d920 (git) Affected: b9873755a6c8ccfce79094c4dce9efa3ecb1a749 , < 3b231f1e9990f4c21220d0a69733ce2105891ff9 (git) |
guessed | |
| Linux | Linux |
Affected:
6.8
Unaffected: 0 , < 6.8 (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.6 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
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"product": "Linux",
"programFiles": [
"drivers/misc/nsm.c"
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"versionType": "git"
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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": [
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"status": "affected",
"version": "6.8"
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{
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"status": "unaffected",
"version": "0",
"versionType": "semver"
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{
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"status": "unaffected",
"version": "6.12.101",
"versionType": "semver"
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{
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"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
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"nodes": [
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{
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"descriptions": [
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"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: nsm: pin the module while the device is open\n\nmisc_open() installs a misc driver\u0027s file operations with fops_get(),\nwhich pins file_operations::owner before replacing the file\u0027s f_op. The\nNSM misc device leaves nsm_dev_fops.owner unset, so opening /dev/nsm does\nnot take a module reference on the nsm driver.\n\nIf the driver is built as a module, an open file descriptor can therefore\nsurvive rmmod of the module that provides its ioctl callbacks. A later\nioctl through that descriptor can call into unloaded module text.\n\nSet nsm_dev_fops.owner to THIS_MODULE so the misc core holds the module\nwhile any /dev/nsm file descriptor is open, matching the lifetime\nexpectation for the installed file operations."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is reached only via local open()/ioctl syscalls on /dev/nsm (misc_open through vfs_ioctl to nsm_dev_ioctl); the Nitro Secure Module virtio driver has no network, adjacent-wireless, or physical attack surface.\nAC:L - When CONFIG_NSM=m the attacker controls the full sequence: open /dev/nsm to install fops, delete_module(\"nsm\") while fops_get(NULL) leaves the module unpinned, then ioctl on the stale fd to call unloaded text without races or external timing.\nPR:L - /dev/nsm is registered mode 0666 with no capable() checks in nsm_dev_ioctl, so any local process can open and ioctl; unloading the module needs CAP_SYS_MODULE, treated as low-privilege local capability per similar module-lifetime UAF scoring on permissive/user-namespace kernels.\nUI:N - The attacker performs open, module removal, and stale-fd ioctl from their own process; no separate victim must mount a filesystem, click a link, or take any action beyond the attacker\u0027s own operations.\nS:U - The use-after-free corrupts guest kernel memory and executes in kernel context within the Nitro Enclave; impact does not cross hypervisor, parent-instance, VM, or IOMMU security boundaries.\nC:H - Stale ioctl calls into freed module text and file_to_nsm() dereferences freed devm nsm state, exposing reclaimed kernel/module memory and adjacent virtio message buffers through the UAF window.\nI:H - Dispatching nsm_dev_ioctl through freed vmalloc module text is a kernel use-after-free that can be shaped with heap spraying to hijack control flow and achieve arbitrary kernel code execution.\nA:H - Executing code from an unloaded module or dereferencing freed nsm/virtqueue state on ioctl reliably causes kernel oops or panic, and the attacker can repeat the stale-fd ioctl to deny service."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:00:19.564Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/1996639f824ce9468395cdb7bcb8f467fa787e77"
},
{
"url": "https://git.kernel.org/stable/c/1da310b94504d42001e9c32c43c5dc105b777e5f"
},
{
"url": "https://git.kernel.org/stable/c/9e9a82d00c3d10129fc310a7547b24a679d5d920"
},
{
"url": "https://git.kernel.org/stable/c/3b231f1e9990f4c21220d0a69733ce2105891ff9"
}
],
"title": "misc: nsm: pin the module while the device is open",
"x_generator": {
"engine": "bippy-1.2.0"
}
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"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2026-68178",
"datePublished": "2026-08-10T11:59:49.344Z",
"dateReserved": "2026-07-30T09:28:09.373Z",
"dateUpdated": "2026-08-17T05:00:19.564Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
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"cve": "CVE-2026-68178",
"date": "2026-09-30",
"epss": "0.00175",
"percentile": "0.06276"
},
"nvd": {
"cve": {
"affected": [
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"affectedData": [
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"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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"versions": [
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},
{
"lessThan": "6.8",
"status": "unaffected",
"version": "0",
"versionType": "semver"
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"version": "6.12.101",
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"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "7.1.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
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"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: nsm: pin the module while the device is open\n\nmisc_open() installs a misc driver\u0027s file operations with fops_get(),\nwhich pins file_operations::owner before replacing the file\u0027s f_op. The\nNSM misc device leaves nsm_dev_fops.owner unset, so opening /dev/nsm does\nnot take a module reference on the nsm driver.\n\nIf the driver is built as a module, an open file descriptor can therefore\nsurvive rmmod of the module that provides its ioctl callbacks. A later\nioctl through that descriptor can call into unloaded module text.\n\nSet nsm_dev_fops.owner to THIS_MODULE so the misc core holds the module\nwhile any /dev/nsm file descriptor is open, matching the lifetime\nexpectation for the installed file operations."
}
],
"id": "CVE-2026-68178",
"lastModified": "2026-08-17T05:18:19.463",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
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},
"published": "2026-08-10T13:20:04.720",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1996639f824ce9468395cdb7bcb8f467fa787e77"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1da310b94504d42001e9c32c43c5dc105b777e5f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"url": "https://git.kernel.org/stable/c/9e9a82d00c3d10129fc310a7547b24a679d5d920"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-08-31T11:17:55+00:00",
"cve": "CVE-2026-68178",
"id": "CVE-2026-68178",
"initial_release_date": "2026-08-10T11:59:49.344000+00:00",
"product_status:known_affected": "1",
"product_status:known_not_affected": "276",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: misc: nsm: pin the module while the device is open",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68178.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "moderate",
"current_release_date": "2026-09-22T16:47:19Z",
"cve": "CVE-2026-68178",
"id": "CVE-2026-68178",
"initial_release_date": "2026-08-13T16:23:32Z",
"product_status:first_fixed": "60",
"product_status:known_not_affected": "374",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-68178",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68178.json",
"version": "3"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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