FKIE_CVE-2026-63823
Vulnerability from fkie_nvd - Published: 2026-07-19 12:16 - Updated: 2026-10-19 20:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
keys: Pin request_key_auth payload in instantiate paths
A: request_key() B: KEYCTL_INSTANTIATE_IOV
================ =========================
create auth key
store rka in auth key
wait for helper
get auth key
load rka from auth key
copy user payload
sleep on #PF
helper completed
detach and free rka
destroy auth key
wake up
use rka->target_key
**USE-AFTER-FREE**
Give request_key_auth payloads a refcount. Take a payload reference while
authkey->sem stabilizes the payload and revocation state. Hold that
reference across the instantiate and reject paths. Drop the auth key
owning reference from revoke and destroy.
[jarkko: Replaced the first two paragraphs of text with an actual
concurrency scenario.]
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/keys/request_key_auth-type.h",
"security/keys/internal.h",
"security/keys/keyctl.c",
"security/keys/request_key_auth.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "d8274181b0f28d450b42489723a5ba81042158d7",
"status": "affected",
"version": "b5f545c880a2a47947ba2118b2509644ab7a2969",
"versionType": "git"
},
{
"lessThan": "4982bfabce6b33b3c9eddb4fb900fe5568b7cf91",
"status": "affected",
"version": "b5f545c880a2a47947ba2118b2509644ab7a2969",
"versionType": "git"
},
{
"lessThan": "708709c65a1832a99b0eef8ae46e343ddaca3d06",
"status": "affected",
"version": "b5f545c880a2a47947ba2118b2509644ab7a2969",
"versionType": "git"
},
{
"lessThan": "35ab4db86774d82389e4b9559e26ab7f68d8e395",
"status": "affected",
"version": "b5f545c880a2a47947ba2118b2509644ab7a2969",
"versionType": "git"
},
{
"lessThan": "f9b68632ac93cc742f2e411021c4dbfe452ea0c2",
"status": "affected",
"version": "b5f545c880a2a47947ba2118b2509644ab7a2969",
"versionType": "git"
},
{
"lessThan": "7216ce8cb12fee44e309503955bb83806b106129",
"status": "affected",
"version": "b5f545c880a2a47947ba2118b2509644ab7a2969",
"versionType": "git"
},
{
"lessThan": "83c0a1cb296d955d5f4d1f0bd8a769ba8ed8c29f",
"status": "affected",
"version": "b5f545c880a2a47947ba2118b2509644ab7a2969",
"versionType": "git"
},
{
"lessThan": "fd15b457a86939c38aa12116adabd8ff686c5e51",
"status": "affected",
"version": "b5f545c880a2a47947ba2118b2509644ab7a2969",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/keys/request_key_auth-type.h",
"security/keys/internal.h",
"security/keys/keyctl.c",
"security/keys/request_key_auth.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.16"
},
{
"lessThan": "2.6.16",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.260",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.211",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.177",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.144",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.95",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.38",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.3",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkeys: Pin request_key_auth payload in instantiate paths\n\nA: request_key() B: KEYCTL_INSTANTIATE_IOV\n================ =========================\n\ncreate auth key\nstore rka in auth key\nwait for helper\n get auth key\n load rka from auth key\n copy user payload\n sleep on #PF\n\nhelper completed\ndetach and free rka\ndestroy auth key\n wake up\n use rka-\u003etarget_key\n **USE-AFTER-FREE**\n\nGive request_key_auth payloads a refcount. Take a payload reference while\nauthkey-\u003esem stabilizes the payload and revocation state. Hold that\nreference across the instantiate and reject paths. Drop the auth key\nowning reference from revoke and destroy.\n\n[jarkko: Replaced the first two paragraphs of text with an actual\n concurrency scenario.]"
}
],
"id": "CVE-2026-63823",
"lastModified": "2026-10-19T20:19:21.803",
"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"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-63823",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-16T15:31:09.788460Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-19T12:16:55.457",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/35ab4db86774d82389e4b9559e26ab7f68d8e395"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4982bfabce6b33b3c9eddb4fb900fe5568b7cf91"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/708709c65a1832a99b0eef8ae46e343ddaca3d06"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7216ce8cb12fee44e309503955bb83806b106129"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/83c0a1cb296d955d5f4d1f0bd8a769ba8ed8c29f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d8274181b0f28d450b42489723a5ba81042158d7"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f9b68632ac93cc742f2e411021c4dbfe452ea0c2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/fd15b457a86939c38aa12116adabd8ff686c5e51"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-416"
}
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
]
}
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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