CVE-2026-46243
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Mitigation details
CVE-2026-46243 NameCVE-2026-46243 DescriptionIn 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…
CVE-2026-46243
| Name | CVE-2026-46243 |
| 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| linux (PTS) | bullseye | 5.10.223-1 | vulnerable |
| bullseye (security) | 5.10.257-1 | fixed | |
| bookworm | 6.1.170-3 | vulnerable | |
| bookworm (security) | 6.1.174-1 | fixed | |
| trixie | 6.12.86-1 | vulnerable | |
| trixie (security) | 6.12.90-2 | fixed | |
| forky | 7.0.9-1 | vulnerable | |
| sid | 7.0.10-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| linux | source | bullseye | 5.10.257-1 | |||
| linux | source | bookworm | 6.1.174-1 | |||
| linux | source | trixie | 6.12.90-2 | |||
| linux | source | (unstable) | 7.0.10-1 |
Notes
https://git.kernel.org/linus/3da1fdf4efbc490041eb4f836bf596201203f8f2 (7.1-rc5)
Apply commands
https://git.kernel.org/linus/3da1fdf4efbc490041eb4f836bf596201203f8f2 (7.1-rc5)OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 6.12.90-2 |
| sid | Fixed | 7.0.10-1 |
| forky | Fixed | 7.0.10-1 |
| bullseye | Fixed | 5.10.257-1 |
| bookworm | Fixed | 6.1.174-1 |
References
- https://git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7
- https://git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079
- https://git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2
- https://git.kernel.org/stable/c/7713bd320ed4fc3d08a227cd8e41242219a16981
- https://git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8
- https://git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824
- https://git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d
- https://git.kernel.org/stable/c/cf20038657d6d4974349556a34e08fe0490bebbc
- https://github.com/manizada/CIFSwitch
- http://www.openwall.com/lists/oss-security/2026/06/01/6
- https://security-tracker.debian.org/tracker/CVE-2026-46243
- https://www.suse.com/security/cve/CVE-2026-46243.html
CWEs
CWE-20
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.