CVE-2026-74608 (GCVE-0-2026-74608)
Vulnerability from cvelistv5
Published
2026-08-22 15:31
Modified
2026-08-25 05:40
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
smb: client: Fix use-after-free in cifs_try_adding_channels()
cifs_try_adding_channels() takes a temporary reference to an interface
before dropping iface_lock. If cifs_ses_add_channel() fails, it drops
that reference and then increments iface->weight_fulfilled.
A concurrent interface list refresh can remove the list reference while
channel creation is in progress. In that case, the failure-path
kref_put() releases the last reference and frees iface. Updating
weight_fulfilled afterward then accesses freed memory.
Increment weight_fulfilled before dropping the temporary reference,
keeping iface alive for the final access.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: cbc53148cc0946b72d62a3c53870cb22ce4ec284 Version: cff97d683a083b862a8bb24309e0f4d2d928128a Version: 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 Version: 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 Version: 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 Version: 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 Version: 22a6c5b3425f327e7f4c3606a72277dce82c7d83 Version: 6.1.78 ≤ Version: 6.6.17 ≤ Version: 6.7.5 ≤ |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/smb/client/sess.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "64d7584e62ac8cdc750455c5fdc6008fc2de4f06",
"status": "affected",
"version": "cbc53148cc0946b72d62a3c53870cb22ce4ec284",
"versionType": "git"
},
{
"lessThan": "c292d4686f717c03e5022fc4ae7c782f39a94915",
"status": "affected",
"version": "cff97d683a083b862a8bb24309e0f4d2d928128a",
"versionType": "git"
},
{
"lessThan": "47dfac48bce7198ad4f1a388fc8c9491f878ac3b",
"status": "affected",
"version": "6aac002bcfd554aff6d3ebb55e1660d078d70ab0",
"versionType": "git"
},
{
"lessThan": "1ffacbadc14530e55b8d86f7b917524f6a0fb891",
"status": "affected",
"version": "6aac002bcfd554aff6d3ebb55e1660d078d70ab0",
"versionType": "git"
},
{
"lessThan": "1305eadc6a7d78a8d0a52eee29ddd2d9e8a27805",
"status": "affected",
"version": "6aac002bcfd554aff6d3ebb55e1660d078d70ab0",
"versionType": "git"
},
{
"lessThan": "4986410316b1ae0e63c6ce418e4eb196723626e7",
"status": "affected",
"version": "6aac002bcfd554aff6d3ebb55e1660d078d70ab0",
"versionType": "git"
},
{
"status": "affected",
"version": "22a6c5b3425f327e7f4c3606a72277dce82c7d83",
"versionType": "git"
},
{
"lessThan": "6.1.183",
"status": "affected",
"version": "6.1.78",
"versionType": "semver"
},
{
"lessThan": "6.6.152",
"status": "affected",
"version": "6.6.17",
"versionType": "semver"
},
{
"lessThan": "6.8",
"status": "affected",
"version": "6.7.5",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/smb/client/sess.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.8"
},
{
"lessThan": "6.8",
"status": "unaffected",
"version": "0",
"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": "6.1.183",
"versionStartIncluding": "6.1.78",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.152",
"versionStartIncluding": "6.6.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.104",
"versionStartIncluding": "6.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.45",
"versionStartIncluding": "6.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.9",
"versionStartIncluding": "6.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.7.5",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: Fix use-after-free in cifs_try_adding_channels()\n\ncifs_try_adding_channels() takes a temporary reference to an interface\nbefore dropping iface_lock. If cifs_ses_add_channel() fails, it drops\nthat reference and then increments iface-\u003eweight_fulfilled.\n\nA concurrent interface list refresh can remove the list reference while\nchannel creation is in progress. In that case, the failure-path\nkref_put() releases the last reference and frees iface. Updating\nweight_fulfilled afterward then accesses freed memory.\n\nIncrement weight_fulfilled before dropping the temporary reference,\nkeeping iface alive for the final access."
}
],
"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 flaw is in the kernel SMB3 client multichannel path reached while handling remote SMB/CIFS server traffic (channel setup, reconnect, and FSCTL_QUERY_NETWORK_INTERFACE_INFO responses) over TCP, so a malicious or compromised SMB server can trigger it from the network.\nAC:L - A hostile SMB server can force cifs_ses_add_channel() to fail and concurrently drive interface-list refresh during the unlocked window; the attacker controls both sides of the race via reconnects, binding failures, and crafted interface responses with retries.\nPR:N - The attacker only needs to operate the malicious SMB server peer; no credentials, local shell access, or privileges on the victim host are required once the client has an SMB3 multichannel session to that server.\nUI:N - After an SMB3 multichannel mount exists, kernel delayed query_interfaces work, automatic reconnect on dropped TCP, and post-mount channel scaling invoke cifs_try_adding_channels() without further user action, letting the server trigger exploitation repeatedly.\nS:U - The UAF corrupts client kernel heap state within the same host kernel security authority and does not inherently cross a VM, container, or IOMMU security boundary.\nC:H - Writing to a freed cifs_server_iface slab object is a use-after-free; attacker-influenced heap grooming can reclaim the object and enable arbitrary kernel memory disclosure via corrupted or overlapping live allocations.\nI:H - The post-free weight_fulfilled increment is a kernel heap write after free that can corrupt adjacent slab objects and be leveraged into arbitrary write or control-flow hijacking through heap shaping.\nA:H - The use-after-free can cause KASAN-detectable slab corruption, kernel oops, or panic, and a malicious server can retrigger it by repeating failed channel opens with concurrent interface-list refresh on reconnect."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-25T05:40:33.533Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/64d7584e62ac8cdc750455c5fdc6008fc2de4f06"
},
{
"url": "https://git.kernel.org/stable/c/c292d4686f717c03e5022fc4ae7c782f39a94915"
},
{
"url": "https://git.kernel.org/stable/c/47dfac48bce7198ad4f1a388fc8c9491f878ac3b"
},
{
"url": "https://git.kernel.org/stable/c/1ffacbadc14530e55b8d86f7b917524f6a0fb891"
},
{
"url": "https://git.kernel.org/stable/c/1305eadc6a7d78a8d0a52eee29ddd2d9e8a27805"
},
{
"url": "https://git.kernel.org/stable/c/4986410316b1ae0e63c6ce418e4eb196723626e7"
}
],
"title": "smb: client: Fix use-after-free in cifs_try_adding_channels()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74608",
"datePublished": "2026-08-22T15:31:55.298Z",
"dateReserved": "2026-08-15T05:44:03.920Z",
"dateUpdated": "2026-08-25T05:40:33.533Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
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.
Loading…
Loading…