In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.spnego descriptions cifs.spnego key… (CVE-2026-46243)
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.
AI Analysis
Technical Summary
The vulnerability CVE-2026-46243 involves the Linux kernel's SMB client rejecting userspace cifs.spnego descriptions improperly. This flaw is addressed in a security update released by Red Hat for Red Hat Enterprise Linux 8 across various supported architectures. The advisory indicates the kernel packages contain the fix and that a reboot is required after applying the update. The CVSS vector provided (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) indicates local attack vector with low complexity, requiring low privileges, no user interaction, and impacts confidentiality, integrity, and availability with high severity.
Potential Impact
Successful exploitation of this vulnerability could allow a local attacker with low privileges to compromise confidentiality, integrity, and availability of the affected system. The vulnerability affects the SMB client in the Linux kernel, potentially leading to significant system compromise if exploited.
Mitigation Recommendations
A security update for the Linux kernel is available from Red Hat for Red Hat Enterprise Linux 8. Users should apply the update as detailed in the Red Hat advisory (https://access.redhat.com/articles/11258) and reboot the system to ensure the fix takes effect. This is an official fix provided by the vendor.
In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.spnego descriptions cifs.spnego key… (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.
CVSS v3.1
Score 7.8high
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-46243 involves the Linux kernel's SMB client rejecting userspace cifs.spnego descriptions improperly. This flaw is addressed in a security update released by Red Hat for Red Hat Enterprise Linux 8 across various supported architectures. The advisory indicates the kernel packages contain the fix and that a reboot is required after applying the update. The CVSS vector provided (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) indicates local attack vector with low complexity, requiring low privileges, no user interaction, and impacts confidentiality, integrity, and availability with high severity.
Potential Impact
Successful exploitation of this vulnerability could allow a local attacker with low privileges to compromise confidentiality, integrity, and availability of the affected system. The vulnerability affects the SMB client in the Linux kernel, potentially leading to significant system compromise if exploited.
Mitigation Recommendations
A security update for the Linux kernel is available from Red Hat for Red Hat Enterprise Linux 8. Users should apply the update as detailed in the Red Hat advisory (https://access.redhat.com/articles/11258) and reboot the system to ensure the fix takes effect. This is an official fix provided by the vendor.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:23259
- Cve Count
- 1
- Additional Cves
- []
- Cvss Version
- 3.1
Threat ID: 6a21eb15e29bf47b50d2416b
Added to database: 06/04/2026, 21:16:05 UTC
Last enriched: 07/16/2026, 15:33:50 UTC
Last updated: 07/31/2026, 19:24:49 UTC
Views: 279
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