Red Hat Samba pam_winbind Home denial of service

Summaryinfo

A vulnerability was found in Red Hat Samba. It has been declared as problematic. Impacted is an unknown function of the component pam_winbind. Executing a manipulation of the argument Home can lead to denial of service. This vulnerability is tracked as CVE-2026-15779. The attack is restricted to local execution. No exploit exists.

Detailsinfo

A vulnerability classified as problematic was found in Red Hat Samba (version now known). This vulnerability affects some unknown processing of the component pam_winbind. The manipulation of the argument HOME with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. CVE summarizes:

A flaw was found in samba's pam_winbind. When mkhomedir is enabled, pam_winbind chowns the target account's home directory without validating the path is not a critical system directory such as /. On affected systems, accounts with / as their home directory (a common default for system accounts) can have this triggered not only by root, but by a non-root user holding a narrow sudo delegation to run commands as that account, causing ownership of / to change and resulting in severe denial of service (SSH, sudo, and package-manager failures). The change does not grant write access to / (which ships with restrictive 0555 permissions on RHEL), so the impact is availability loss rather than further privilege escalation.

The advisory is shared for download at access.redhat.com. This vulnerability was named CVE-2026-15779 since 07/14/2026. The exploitation appears to be easy. The attack needs to be approached locally. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/15/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• File Transfer Software

Vendor

• Red Hat

Name

• Samba

License

• open-source

Website

• Vendor: https://www.redhat.com/

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