{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43378", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.006Z", "datePublished": "2026-05-08T14:21:27.319Z", "dateUpdated": "2026-08-05T12:27:38.612Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:27:38.612Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: server: fix use-after-free in smb2_open()\n\nThe opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is\ndereferenced after rcu_read_unlock(), creating a use-after-free\nwindow." } ], "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 vulnerable path is ksmbd's SMB2 CREATE handler, reachable over the SMB server network listener on TCP/445 or SMB Direct. A remote client can drive the request path to `smb2_open()`.\nAC:L - The bug is a UAF window around concurrent oplock/lease state changes, and an attacker can create concurrent SMB opens/lease breaks using multiple requests or connections. Under the rule to choose higher severity when uncertain, this is Low complexity.\nPR:N - `SMB2_CREATE` requires a valid session and tree connection, but ksmbd supports guest/anonymous SMB sessions and guest shares in a reasonable deployment. In that scenario no prior credentials are required.\nUI:N - Exploitation is driven entirely by network SMB requests. No victim user action is required after the server is running.\nS:U - The vulnerability is in the kernel SMB server and impacts the same host kernel security authority. It does not inherently cross a VM, hypervisor, or separate security scope boundary.\nC:H - The flaw is a use-after-free of `struct oplock_info` and its lease data after RCU protection is dropped. Kernel UAF memory corruption can be leveraged for high-impact information disclosure.\nI:H - The dangling `oplock_info` pointer can be used after free while building the SMB2 CREATE response, creating exploitable kernel memory corruption. UAFs are treated as capable of arbitrary write or control-flow impact.\nA:H - A remotely triggerable kernel UAF can cause an oops, panic, or service crash. Repeated SMB requests can make the availability impact high." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/smb2pdu.c" ], "versions": [ { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "e1b21e6066615e7d3d3a7aa2677e415e563fd7cc", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "b720c84087cb547f23ce03eab93568c1769e4556", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "54b48ae83de8bb06e65079d96368efe359d4909c", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "8f5b1a7cb009a93c48e9e334a2f59a660f9afc07", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "190e5f808e8058640b408ccfed25440b441a718a", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "1e689a56173827669a35da7cb2a3c78ed5c53680", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/smb2pdu.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.19", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.9", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "5.15", "versionEndExcluding": "6.1.167" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.78" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.19.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e1b21e6066615e7d3d3a7aa2677e415e563fd7cc" }, { "url": "https://git.kernel.org/stable/c/b720c84087cb547f23ce03eab93568c1769e4556" }, { "url": "https://git.kernel.org/stable/c/54b48ae83de8bb06e65079d96368efe359d4909c" }, { "url": "https://git.kernel.org/stable/c/8f5b1a7cb009a93c48e9e334a2f59a660f9afc07" }, { "url": "https://git.kernel.org/stable/c/190e5f808e8058640b408ccfed25440b441a718a" }, { "url": "https://git.kernel.org/stable/c/1e689a56173827669a35da7cb2a3c78ed5c53680" } ], "title": "smb: server: fix use-after-free in smb2_open()", "x_generator": { "engine": "bippy-1.2.0" } } } }