CVE-2026-12505

Cifs-utils: local privilege escalation via forged cifs.spnego key description in cifs.upcall

publishedCWE-250

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.

Technical severity7.8 highCVSS 3.1 · CNA: redhat

Published2026-06-18Source updated 2026-11-03

Collected2026-11-032 attributed sources

Fixes and workarounds

Workaround

Red Hat is not aware of a practical temporary workaround that fully mitigates this issue or meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the relevant security updates when they become available.

Source: CNA: redhat

Fix

RHSA-2026:44232: Red Hat OpenShift Container Platform 4.22 RHSA-2026:32990: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) RHSA-2026:39576: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) RHSA-2026:39575: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8)

Source: ADP: redhat-SADP

Workaround

Source: ADP: redhat-SADP

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
Red Hat Enterprise Linux 10 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	≥ 0:7.6-1.el10_2; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	≥ 0:7.0-5.el8_10; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	≥ 0:7.6-2.el9_8; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat OpenShift Container Platform 4.22 Red Hat `openshift/ose-rhel-coreos-9` https://access.redhat.com/downloads/content/package-browser/	≥ 4.22.9.8.202607220526-0; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 6 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 7 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unaffected	CNA: redhat
Red Hat OpenShift Container Platform 4 Red Hat `openshift/ose-rhel-coreos-8` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: affected	CNA: redhat
Red Hat OpenShift Container Platform 5 Red Hat `openshift/ose-rhel-coreos-9` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 10 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	≥ 0:7.6-1.el10_2; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 8 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	≥ 0:7.0-5.el8_10; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 9 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	≥ 0:7.6-2.el9_8; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat OpenShift Container Platform 4.22 Red Hat `rhcos` https://access.redhat.com/downloads/content/package-browser/	≥ 4.22.9.8.202607220526-0; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 6 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	ADP: redhat-SADP
Red Hat Enterprise Linux 7 Red Hat `cifs-utils` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unaffected	ADP: redhat-SADP

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 7.8 high	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`	CNA: redhat
3.1 / 7.8 high	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`	ADP: redhat-SADP

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://access.redhat.com/errata/RHSA-2026:32990CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:39575CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:39576CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:44232CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-12505CNA: redhat · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2489805CNA: redhat · issue-tracking, x_refsource_REDHAT
https://git.samba.org/?p=cifs-utils.git;a=commit;h=972c5b5ff95e3e812bc8daa72d0383654ab0dba7CNA: redhat
https://access.redhat.com/security/cve/CVE-2026-12505ADP: redhat-SADP · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2489805ADP: redhat-SADP · issue-tracking, x_refsource_REDHAT
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12505.jsonADP: redhat-SADP · x_sadp-csaf-vex
https://access.redhat.com/errata/RHSA-2026:44232ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:32990ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:39576ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:39575ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT

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