CVE-2026-12505
HIGHDescription
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.
How to fix
This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 5% of all known CVEs.
References
Related Vulnerabilities
Other CWE-250 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-1222 | High | 8.6 | 64% | - | Fix |
| CVE-2025-12420 | Critical | 9.8 | 46% | - | Fix |
| CVE-2024-38813 | High | 7.5 | 17% | KEV | Fix |
| CVE-2026-29205 | High | 8.6 | 8.2% | - | Fix |
| CVE-2025-34515 | Critical | 9.8 | 7.4% | - | - |
| CVE-2019-16765 | High | 7.4 | 5.0% | - | Fix |
Common questions
How do I fix CVE-2026-12505?
Published advisories record a fix for 21 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2026-12505 being actively exploited?
Not that we know of. CVE-2026-12505 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.16% is the estimated probability that it will be exploited in the next 30 days. That is higher than 5% of all scored CVEs.
How severe is CVE-2026-12505?
CVE-2026-12505 has a CVSS v3 base score of 7.8, rated important. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-12505 affect?
Published advisories record a fix for cifs-utils (Red Hat / RHEL), cifs-utils (Rocky), cifs-utils-debuginfo (Rocky), cifs-utils-debuginfo (Red Hat / RHEL), and 17 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-25.