{"id":"CVE-2026-64380","summary":"smb: client: harden POSIX SID length parsing","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: harden POSIX SID length parsing\n\nposix_info_sid_size() reads sid[1] to obtain the subauthority count,\nbut its existing boundary check still accepts buffers with only one\nremaining byte. Require two bytes before reading sid[1] so all client\npaths that reuse the helper reject truncated POSIX SIDs safely.","modified":"2026-08-18T03:31:11.179581853Z","published":"2026-07-25T08:50:30.476Z","related":["openSUSE-SU-2026:11476-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64380.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0de5b8e76847f5de26f364a82c6602c4881c30da"},{"type":"WEB","url":"https://git.kernel.org/stable/c/171605aed68380c2fa75dff9b3a1ed427c50065b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4213c1208978483021d7d125c131de3985d38f61"},{"type":"WEB","url":"https://git.kernel.org/stable/c/427eb7eb46425fec845a43e861f3d6e2899cae59"},{"type":"WEB","url":"https://git.kernel.org/stable/c/46a84715a015cb48e1b9c219dc88c03d8a541ea4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7ad2bcf2441430bb2e918fb3ef9a90d775a6e422"},{"type":"WEB","url":"https://git.kernel.org/stable/c/86c5d470f5d42e61123b2f4b4f0b91f4eee5b980"},{"type":"WEB","url":"https://git.kernel.org/stable/c/96e889bc1e759c83f25093e8c2f3da31b4973f30"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64380.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64380"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"349e13ad30b45998bb9937cfe0b32be6f951976d"},{"fixed":"171605aed68380c2fa75dff9b3a1ed427c50065b"},{"fixed":"4213c1208978483021d7d125c131de3985d38f61"},{"fixed":"96e889bc1e759c83f25093e8c2f3da31b4973f30"},{"fixed":"0de5b8e76847f5de26f364a82c6602c4881c30da"},{"fixed":"427eb7eb46425fec845a43e861f3d6e2899cae59"},{"fixed":"86c5d470f5d42e61123b2f4b4f0b91f4eee5b980"},{"fixed":"46a84715a015cb48e1b9c219dc88c03d8a541ea4"},{"fixed":"7ad2bcf2441430bb2e918fb3ef9a90d775a6e422"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64380.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.7.0"},{"fixed":"5.10.261"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.96"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.39"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64380.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H"}]}