CVE-2026-98171
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs Fix several related bounds checking and pointer lifecycle issues in receive_encrypted_standard()'s handling of compound encrypted frames: - Clear next_buffer after assigning it to server->bigbuf. A stale next_buffer pointer can lead to a use-after-free on subsequent error paths. - Update pdu_length to the decrypted plaintext size (buf_size). Using the pre-decryption length allows NextCommand to point into stale ciphertext residue. - Reject next_cmd values smaller than MID_HEADER_SIZE(server). - Fix an integer overflow in the upper bound check by verifying pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the trailing slice is large enough for a header.
Severity
HIGH
CVSS score
8.8
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-06 09:17:58.773000
Last modified
2026-10-30 13:21:11.360000
View original CVE JSON
{
"id": "CVE-2026-98171",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-06T09:17:58.773",
"lastModified": "2026-10-30T13:21:11.360",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs\n\nFix several related bounds checking and pointer lifecycle issues in\nreceive_encrypted_standard()'s handling of compound encrypted frames:\n\n- Clear next_buffer after assigning it to server->bigbuf. A stale\n next_buffer pointer can lead to a use-after-free on subsequent\n error paths.\n- Update pdu_length to the decrypted plaintext size (buf_size). Using\n the pre-decryption length allows NextCommand to point into stale\n ciphertext residue.\n- Reject next_cmd values smaller than MID_HEADER_SIZE(server).\n- Fix an integer overflow in the upper bound check by verifying\n pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the\n trailing slice is large enough for a header."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/smb/client/smb2ops.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "b24df3e30cbf48255db866720fb71f14bf9d2f39",
"lessThan": "1ed29f7a03417b405f38c09cfe04124883127b53",
"versionType": "git",
"status": "affected"
},
{
"version": "b24df3e30cbf48255db866720fb71f14bf9d2f39",
"lessThan": "7f022867ec9f0166a0b4400385bb601b1c6b2c75",
"versionType": "git",
"status": "affected"
},
{
"version": "b24df3e30cbf48255db866720fb71f14bf9d2f39",
"lessThan": "72eaef1f37a3b6bec11c342736834dc3707be3e4",
"versionType": "git",
"status": "affected"
},
{
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"status": "affected"
},
{
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"versionType": "git",
"status": "affected"
},
{
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"lessThan": "96c436e4b010711452b2872558938f4ef276492a",
"versionType": "git",
"status": "affected"
},
{
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"lessThan": "858d5ac22cb889266993e7670f9f0c4f4aeedd78",
"versionType": "git",
"status": "affected"
},
{
"version": "b24df3e30cbf48255db866720fb71f14bf9d2f39",
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"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/smb/client/smb2ops.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.19",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.19",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.273",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.224",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.189",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.158",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.112",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.54",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.8",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "REQUIRED",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/05762c5bc1cfdcac36747994fde2c04387a457f1",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/1ed29f7a03417b405f38c09cfe04124883127b53",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/491e33144dee872cffda207f6fcb09260728f803",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/72eaef1f37a3b6bec11c342736834dc3707be3e4",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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},
{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8749946579708ea0d339034bb7f423a67dbe89cf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/96c436e4b010711452b2872558938f4ef276492a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}