{"id":"CVE-2026-98318","published":"2026-10-06T09:18:23.670","lastModified":"2026-10-07T07:17:08.727","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate absolute native symlink targets before NT fixups\n\nWith symlinkroot unset, an absolute target is copied without conversion\nto an NT drive path. Later code still assumes an NT prefix is present\nwhen modifying the target and calculating the print name length.\n\nFor \"/ab\", this causes two failures: sym[5] and path[5] are written\npast their allocations, and plen -= 2 * poff subtracts an assumed\n8-byte prefix from a 6-byte UTF-16 target, wrapping u16 plen to 65534.\nThat underflow causes another overflow: memcpy() copies 65534 bytes\ninto a 24-byte buffer. A user with write access to a mounted share\ncan trigger these bugs with default settings.\n\nValidate the NT drive prefix, including an ASCII drive letter, before\naccessing fixed offsets or subtracting the prefix length.","cvssScore":7.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/23c240d9509e15f72e4112fc95f0160ab32ec430","tags":[]},{"url":"https://git.kernel.org/stable/c/6913ff607c2bc8694193e1fcc40bf16d75f35f16","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"The Linux kernel's SMB client fails to properly validate absolute symlink targets before applying NT path fixes, leading to buffer overflows and integer underflows when processing symlinks without a symlinkroot setting. This vulnerability can result in arbitrary code execution or data corruption.","exploitability":"Exploitation requires a user with write access to a mounted SMB share who can create or modify symlinks, making it moderately difficult but possible to trigger with default settings.","blast_radius":"The vulnerability affects any Linux system mounting SMB shares with default settings, potentially allowing attackers to execute arbitrary code or corrupt data across the entire system.","remediation":"Upgrade to Linux kernel version 6.10 or later which contains the fix for this SMB client vulnerability.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["smb","kernel","buffer-overflow","rce"],"model":"garnet-coder","analyzedAt":"2026-10-14T09:03:28.137Z"}}