CVE-2026-98318
smb: client: validate absolute native symlink targets before NT fixups
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.
INFO
Published Date :
Oct. 6, 2026, 9:18 a.m.
Last Modified :
Oct. 6, 2026, 9:18 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the patched version.
- Validate symlink targets rigorously.
- Ensure NT drive prefix handling is correct.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-98318.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/23c240d9509e15f72e4112fc95f0160ab32ec430 | |
| https://git.kernel.org/stable/c/6913ff607c2bc8694193e1fcc40bf16d75f35f16 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-98318 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-98318
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-98318 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-98318 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 06, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98318.json">CVE-2026-98318</a> Added Reference https://git.kernel.org/stable/c/23c240d9509e15f72e4112fc95f0160ab32ec430 Added Reference https://git.kernel.org/stable/c/6913ff607c2bc8694193e1fcc40bf16d75f35f16