{"id":"CVE-2026-31478","title":"ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()\n\nAfter this commit (e2b76ab8b5c9 \"ksmbd: add support for read compound\"),\nresponse buff…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= f2283680a80571ca82d710bc6ecd8f8beac67d63 < 70b4c414889492c522b6e4331562360f49be2361","Linux >= 9f297df20d93411c0b4ddad7f88ba04a7cd36e77 < 9a7166f0ef8cbb7bb48dd05e2471d995566003f5","Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < c3a89e3ec1ccf64fa6a34e391e1581ebbcba8683","Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 6aef1765d6807e0f027cd87f6ac973eb0879a46d","Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 80824c7e527b70cf9039534e60aff592e8f209d1","Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 4cb537ae4f37d7d0f617815ed4bed7173fb50861","Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 0e55f63dd08f09651d39e1b709a91705a8a0ddcb","Linux >= 5.15.145 < 5.15.203","Linux >= 6.1.71 < 6.1.168","Linux 6.6"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:09:58.409155Z"},"published":"2026-04-22","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:12.684Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31478","references":[{"url":"https://git.kernel.org/stable/c/70b4c414889492c522b6e4331562360f49be2361"},{"url":"https://git.kernel.org/stable/c/9a7166f0ef8cbb7bb48dd05e2471d995566003f5"},{"url":"https://git.kernel.org/stable/c/c3a89e3ec1ccf64fa6a34e391e1581ebbcba8683"},{"url":"https://git.kernel.org/stable/c/6aef1765d6807e0f027cd87f6ac973eb0879a46d"},{"url":"https://git.kernel.org/stable/c/80824c7e527b70cf9039534e60aff592e8f209d1"},{"url":"https://git.kernel.org/stable/c/4cb537ae4f37d7d0f617815ed4bed7173fb50861"},{"url":"https://git.kernel.org/stable/c/0e55f63dd08f09651d39e1b709a91705a8a0ddcb"}],"tags":["cve.org"],"epss":0.00738,"epssPercentile":0.53607,"ingestedAt":"2026-10-16T17:24:46.656Z","slug":"CVE-2026-31478","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()\n\nAfter this commit (e2b76ab8b5c9 \"ksmbd: add support for read compound\"),\nresponse buffer management was changed to use dynamic iov array.\nIn the new design, smb2_calc_max_out_buf_len() expects the second\nargument (hdr2_len) to be the offset of ->Buffer field in the\nresponse structure, not a hardcoded magic number.\nFix the remaining call sites to use the correct offsetof() value.\n\n## Affected\n\n- `Linux >= f2283680a80571ca82d710bc6ecd8f8beac67d63 < 70b4c414889492c522b6e4331562360f49be2361`\n- `Linux >= 9f297df20d93411c0b4ddad7f88ba04a7cd36e77 < 9a7166f0ef8cbb7bb48dd05e2471d995566003f5`\n- `Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < c3a89e3ec1ccf64fa6a34e391e1581ebbcba8683`\n- `Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 6aef1765d6807e0f027cd87f6ac973eb0879a46d`\n- `Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 80824c7e527b70cf9039534e60aff592e8f209d1`\n- `Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 4cb537ae4f37d7d0f617815ed4bed7173fb50861`\n- `Linux >= e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d < 0e55f63dd08f09651d39e1b709a91705a8a0ddcb`\n- `Linux >= 5.15.145 < 5.15.203`\n- `Linux >= 6.1.71 < 6.1.168`\n- `Linux 6.6`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}