A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This forces the system to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary commands as the root user, elevating their privileges and fully compromising the system.

amazon_alas ALAS2023-2026-1927: Amazon Linux 2023 Security Advisory:ALAS2023-2026-1927

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2026:0552 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2026-12505:
    A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root     privileges before looking up user information inside a user-controlled environment. A local, low     privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper     into entering a custom environment (namespace) containing a malicious NSS module. This forces the system     to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary     commands as the root user, elevating their privileges and fully compromising the system.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 45 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-90dbff48ca advisory.

    Automatic update for cifs-utils-7.6-2.fc45.

    ##### **Changelog**

    ```
    * Mon Jul  6 2026 Paulo Alcantara <paalcant@redhat.com> - 7.6-2
    - cifs.upcall: fix regression with kerberos mounts
    - Resolves: rhbz#2497446
    - Resolves: rhbz#2496963
    - Resolves: rhbz#2489808 - CVE-2026-12505

    ```

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote RockyLinux 10 host has packages installed that are affected by a vulnerability as referenced in the RLSA-2026:32990 advisory.

    * cifs-utils: local privilege escalation via forged cifs.spnego key description in cifs.upcall     (CVE-2026-12505)

Tenable has extracted the preceding description block directly from the RockyLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has a package installed that is affected by a vulnerability as referenced in the USN-8496-1 advisory.

    It was discovered that cifs-utils incorrectly dropped root privileges before looking up user information.
    A local attacker could possibly use this issue to execute arbitrary code as the root user.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of CBL-Mariner Releases installed on the remote Azure Linux 3.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2026-12505 advisory.

  - A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root     privileges before looking up user information inside a user-controlled environment. A local, low     privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper     into entering a custom environment (namespace) containing a malicious NSS module. This forces the system     to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary     commands as the root user, elevating their privileges and fully compromising the system. (CVE-2026-12505)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by a vulnerability as referenced in the SUSE-SU-2026:2699-1 advisory.

    This update for cifs-utils fixes the following issue

    - CVE-2026-12505: cifs.upcall local privilege escalation via request_key-controlled namespace switch and     NSS loading       (bsc#1267389).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 host has packages installed that are affected by a vulnerability as referenced in the SUSE- SU-2026:2700-1 advisory.

    This update for cifs-utils fixes the following issue

    - CVE-2026-12505: cifs.upcall local privilege escalation via request_key-controlled namespace switch and     NSS loading       (bsc#1267389).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 10 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:32990 advisory.

    The SMB/CIFS protocol is a standard file sharing protocol widely deployed on Microsoft Windows machines.
    The cifs-utils packages contain tools for mounting shares on Linux using the SMB/CIFS protocol. The tools     in this package work in conjunction with support in the kernel to allow one to mount a SMB/CIFS share onto     a client and use it as if it were a standard Linux file system.

    Security Fix(es):

    * cifs-utils: local privilege escalation via forged cifs.spnego key description in cifs.upcall     (CVE-2026-12505)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root     privileges before looking up user information inside a user-controlled environment. A local, low     privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper     into entering a custom environment (namespace) containing a malicious NSS module. This forces the system     to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary     commands as the root user, elevating their privileges and fully compromising the system. (CVE-2026-12505)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
325858	TencentOS Server 4: cifs-utils (TSSA-2026:0552)	Nessus	Tencent Local Security Checks	high
325312	Fedora 45 : cifs-utils (2026-90dbff48ca)	Nessus	Fedora Local Security Checks	high
325197	RockyLinux 10 : cifs-utils (RLSA-2026:32990)	Nessus	Rocky Linux Local Security Checks	high
325004	Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : cifs-utils vulnerability (USN-8496-1)	Nessus	Ubuntu Local Security Checks	high
324921	Azure Linux 3.0 Security Update: CBL-Mariner Releases (CVE-2026-12505)	Nessus	Azure Linux Local Security Checks	high
324868	SUSE SLED15 / SLES15 Security Update : cifs-utils (SUSE-SU-2026:2699-1)	Nessus	SuSE Local Security Checks	high
324839	SUSE SLES12 Security Update : cifs-utils (SUSE-SU-2026:2700-1)	Nessus	SuSE Local Security Checks	high
323869	RHEL 10 : cifs-utils (RHSA-2026:32990)	Nessus	Red Hat Local Security Checks	high
321661	Linux Distros Unpatched Vulnerability : CVE-2026-12505	Nessus	Misc.	high

Detections

Analytics

CVE-2026-12505

high

Tenable Plugins

Coming Soon

high

high

high

high

high

high

high

high

high