{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68343", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.384Z", "datePublished": "2026-08-10T12:03:19.939Z", "dateUpdated": "2026-08-19T16:33:43.025Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:33:43.025Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate DFS referral PathConsumed\n\nparse_dfs_referrals() validates that the response contains the fixed\nreferral entry array and, on for-next, the per-referral string offsets.\nHowever, the response also contains a PathConsumed value that is later\nused for DFS path parsing.\n\nIf a malformed response provides a PathConsumed value larger than the\nsearch name, later DFS parsing can advance beyond the end of the path.\n\nValidate PathConsumed against the search name length before storing it in\nthe parsed referral." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The tainted PathConsumed value comes directly from a GET_DFS_REFERRAL response received over TCP/445 from the SMB server, so a malicious or MITM-positioned server on the network fully controls the input to the vulnerable code.\nAC:L - The server simply sets an oversized PathConsumed (up to 65535, and it can also clear the SMB1 UNICODE flag to select the completely unvalidated branch); the resulting out-of-bounds walk past the path buffer is deterministic and needs no race or memory-layout luck.\nPR:N - The attacker is the remote server (or a MITM on an unsigned connection) and needs no account or privilege on the victim client; the client parses the referral response as part of establishing the connection.\nUI:N - DFS referral walks are performed automatically by autofs/systemd automounts, fstab mounts at boot and reconnect-driven remounts, so a forged referral can be delivered without any user action.\nS:U - The out-of-bounds access stays within the kernel's own memory and mount context on the client; no VM, IOMMU or sandbox boundary is crossed.\nC:H - prepath = full_path + path_consumed points past the end of the heap path string, and cifs_build_devname() strlen()s and copies from there, splicing adjacent kernel heap contents (up to ~64KB away) into the constructed UNC/prefixpath that is then observable via the mount source and /proc/mounts.\nI:N - The defect is purely an out-of-bounds read; all subsequent allocations and copies are sized from the same over-read string, so no kernel memory is written or corrupted.\nA:H - With PathConsumed up to 65535 the pointer can run far past a small slab object into an unmapped or guarded page, so strlen() on it oopses the mounting task (and panics on panic_on_oops systems)." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/misc.c" ], "versions": [ { "version": "4ecce920e13ace16a5ba45efe8909946c28fb2ad", "lessThan": "bfebe5110fd135d86d65a0a346e14c106b02028b", "status": "affected", "versionType": "git" }, { "version": "4ecce920e13ace16a5ba45efe8909946c28fb2ad", "lessThan": "5b439f39f33ec15d319ced3b025e122346fba987", "status": "affected", "versionType": "git" }, { "version": "4ecce920e13ace16a5ba45efe8909946c28fb2ad", "lessThan": "285bd4a5f3f156aa5869843b47a1b1380b774241", "status": "affected", "versionType": "git" }, { "version": "4ecce920e13ace16a5ba45efe8909946c28fb2ad", "lessThan": "2fdd6d196c656b376cc251e1e9ff110b3ed522e1", "status": "affected", "versionType": "git" }, { "version": "4ecce920e13ace16a5ba45efe8909946c28fb2ad", "lessThan": "9f88a99ed511651b2dc2177d6854b2d1b8322e75", "status": "affected", "versionType": "git" }, { "version": "4ecce920e13ace16a5ba45efe8909946c28fb2ad", "lessThan": "f6f5ee2aa33b350c671721b965251c42cebb962e", "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/client/misc.c" ], "versions": [ { "version": "4.11", "status": "affected" }, { "version": "0", "lessThan": "4.11", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "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": "4.11", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bfebe5110fd135d86d65a0a346e14c106b02028b" }, { "url": "https://git.kernel.org/stable/c/5b439f39f33ec15d319ced3b025e122346fba987" }, { "url": "https://git.kernel.org/stable/c/285bd4a5f3f156aa5869843b47a1b1380b774241" }, { "url": "https://git.kernel.org/stable/c/2fdd6d196c656b376cc251e1e9ff110b3ed522e1" }, { "url": "https://git.kernel.org/stable/c/9f88a99ed511651b2dc2177d6854b2d1b8322e75" }, { "url": "https://git.kernel.org/stable/c/f6f5ee2aa33b350c671721b965251c42cebb962e" } ], "title": "smb: client: validate DFS referral PathConsumed", "x_generator": { "engine": "bippy-1.2.0" } } } }