CVE-2026-46243
smb: client: reject userspace cifs.spnego descriptions
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.spnego descriptions cifs.spnego key descriptions contain authority-bearing fields such as pid, uid, creduid, and upcall_target that cifs.upcall treats as kernel-originating inputs. However, userspace can also create keys of this type through request_key(2) or add_key(2), allowing those fields to be supplied without CIFS origin. Only accept cifs.spnego descriptions while CIFS is using its private spnego_cred to request the key.
INFO
Published Date :
June 1, 2026, 5:17 p.m.
Last Modified :
June 1, 2026, 5:57 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-46243
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel to include the fix.
- Ensure CIFS uses private spnego_cred for key requests.
- Monitor key creation for unauthorized sources.
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-2026-46243.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-46243 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-2026-46243
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-2026-46243 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-46243 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.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 01, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.spnego descriptions cifs.spnego key descriptions contain authority-bearing fields such as pid, uid, creduid, and upcall_target that cifs.upcall treats as kernel-originating inputs. However, userspace can also create keys of this type through request_key(2) or add_key(2), allowing those fields to be supplied without CIFS origin. Only accept cifs.spnego descriptions while CIFS is using its private spnego_cred to request the key. Added Reference https://git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7 Added Reference https://git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079 Added Reference https://git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2 Added Reference https://git.kernel.org/stable/c/7713bd320ed4fc3d08a227cd8e41242219a16981 Added Reference https://git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8 Added Reference https://git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824 Added Reference https://git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d Added Reference https://git.kernel.org/stable/c/cf20038657d6d4974349556a34e08fe0490bebbc