CVE-2026-98318

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

smb: client: validate absolute native symlink targets before NT fixups

With symlinkroot unset, an absolute target is copied without conversion

to an NT drive path. Later code still assumes an NT prefix is present

when modifying the target and calculating the print name length.

For "/ab", this causes two failures: sym[5] and path[5] are written

past their allocations, and plen -= 2 * poff subtracts an assumed

8-byte prefix from a 6-byte UTF-16 target, wrapping u16 plen to 65534.

That underflow causes another overflow: memcpy() copies 65534 bytes

into a 24-byte buffer. A user with write access to a mounted share

can trigger these bugs with default settings.

Validate the NT drive prefix, including an ASCII drive letter, before

accessing fixed offsets or subtracting the prefix length.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References