{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74608", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.920Z", "datePublished": "2026-08-22T15:31:55.298Z", "dateUpdated": "2026-10-16T19:06:00.915Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:33.533Z" }, "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->weight_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": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/sess.c" ], "versions": [ { "version": "cbc53148cc0946b72d62a3c53870cb22ce4ec284", "lessThan": "64d7584e62ac8cdc750455c5fdc6008fc2de4f06", "status": "affected", "versionType": "git" }, { "version": "cff97d683a083b862a8bb24309e0f4d2d928128a", "lessThan": "c292d4686f717c03e5022fc4ae7c782f39a94915", "status": "affected", "versionType": "git" }, { "version": "6aac002bcfd554aff6d3ebb55e1660d078d70ab0", "lessThan": "47dfac48bce7198ad4f1a388fc8c9491f878ac3b", "status": "affected", "versionType": "git" }, { "version": "6aac002bcfd554aff6d3ebb55e1660d078d70ab0", "lessThan": "1ffacbadc14530e55b8d86f7b917524f6a0fb891", "status": "affected", "versionType": "git" }, { "version": "6aac002bcfd554aff6d3ebb55e1660d078d70ab0", "lessThan": "1305eadc6a7d78a8d0a52eee29ddd2d9e8a27805", "status": "affected", "versionType": "git" }, { "version": "6aac002bcfd554aff6d3ebb55e1660d078d70ab0", "lessThan": "4986410316b1ae0e63c6ce418e4eb196723626e7", "status": "affected", "versionType": "git" }, { "version": "22a6c5b3425f327e7f4c3606a72277dce82c7d83", "status": "affected", "versionType": "git" }, { "version": "6.1.78", "lessThan": "6.1.183", "status": "affected", "versionType": "semver" }, { "version": "6.6.17", "lessThan": "6.6.152", "status": "affected", "versionType": "semver" }, { "version": "6.7.5", "lessThan": "6.8", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/sess.c" ], "versions": [ { "version": "6.8", "status": "affected" }, { "version": "0", "lessThan": "6.8", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.78", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.17", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7.5" } ] } ] } ], "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" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74608", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:02:11.593248Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:06:00.915Z" } } ] } }