{"id":"CVE-2026-68343","state":"PUBLISHED","title":"smb: client: validate DFS referral PathConsumed","description":"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.","publishedAt":"2026-08-10T12:03:19.939Z","updatedAt":"2026-10-19T21:09:05.575Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"bfebe5110fd135d86d65a0a346e14c106b02028b","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"5b439f39f33ec15d319ced3b025e122346fba987","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"285bd4a5f3f156aa5869843b47a1b1380b774241","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"2fdd6d196c656b376cc251e1e9ff110b3ed522e1","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"9f88a99ed511651b2dc2177d6854b2d1b8322e75","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"f6f5ee2aa33b350c671721b965251c42cebb962e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/misc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.11","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/misc.c"]}],"references":["https://git.kernel.org/stable/c/bfebe5110fd135d86d65a0a346e14c106b02028b","https://git.kernel.org/stable/c/5b439f39f33ec15d319ced3b025e122346fba987","https://git.kernel.org/stable/c/285bd4a5f3f156aa5869843b47a1b1380b774241","https://git.kernel.org/stable/c/2fdd6d196c656b376cc251e1e9ff110b3ed522e1","https://git.kernel.org/stable/c/9f88a99ed511651b2dc2177d6854b2d1b8322e75","https://git.kernel.org/stable/c/f6f5ee2aa33b350c671721b965251c42cebb962e"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68343.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68343","state":"PUBLISHED","datePublished":"2026-08-10T12:03:19.939Z","dateUpdated":"2026-10-19T21:09:05.575Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.384Z"},"containers":{"cna":{"title":"smb: client: validate DFS referral PathConsumed","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"bfebe5110fd135d86d65a0a346e14c106b02028b","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"5b439f39f33ec15d319ced3b025e122346fba987","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"285bd4a5f3f156aa5869843b47a1b1380b774241","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"2fdd6d196c656b376cc251e1e9ff110b3ed522e1","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"9f88a99ed511651b2dc2177d6854b2d1b8322e75","versionType":"git"},{"version":"4ecce920e13ace16a5ba45efe8909946c28fb2ad","status":"affected","lessThan":"f6f5ee2aa33b350c671721b965251c42cebb962e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/misc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.11","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/misc.c"]}],"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"}],"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)."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:33:43.025Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-68343","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:47:19.145050Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T21:09:05.575Z"}}]}}}