{"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": "2026-08-25T05:40:33.533Z"}, "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"}}}}

{}

{"affected": [{"affectedData": [{"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"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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."}], "id": "CVE-2026-74608", "lastModified": "2026-08-25T06:18:37.637", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-22T16:16:33.290", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1305eadc6a7d78a8d0a52eee29ddd2d9e8a27805"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1ffacbadc14530e55b8d86f7b917524f6a0fb891"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/47dfac48bce7198ad4f1a388fc8c9491f878ac3b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4986410316b1ae0e63c6ce418e4eb196723626e7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/64d7584e62ac8cdc750455c5fdc6008fc2de4f06"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c292d4686f717c03e5022fc4ae7c782f39a94915"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: smb: client: Fix use-after-free in cifs_try_adding_channels()", "id": "2521415", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521415"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nsmb: client: Fix use-after-free in cifs_try_adding_channels()\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.\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.\nIncrement weight_fulfilled before dropping the temporary reference,\nkeeping iface alive for the final access.", "A flaw was found in the Server Message Block (SMB) client of the Linux kernel. A use-after-free vulnerability exists in the `cifs_try_adding_channels()` function. This occurs when a concurrent interface list refresh removes a reference to an interface while a channel creation is in progress and fails, leading to the system attempting to access memory that has already been freed. This could result in a denial of service or potentially lead to arbitrary code execution."], "name": "CVE-2026-74608", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74608\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74608\nhttps://lore.kernel.org/linux-cve-announce/2026082216-CVE-2026-74608-dfb0@gregkh/T"], "threat_severity": "Moderate"}