CVE-2026-15779
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 /…
Does this matter?
Lower severity and a low EPSS score (0.10%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
- EPSS
- 0.10% probability · 1th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-732
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2026-15779
- https://bugzilla.redhat.com/show_bug.cgi?id=2499991
- https://gitlab.com/samba-team/samba/-/blob/samba-4.19.4/nsswitch/pam_winbind.c
- https://gitlab.com/samba-team/samba/-/blob/samba-4.23.5/nsswitch/pam_winbind.c#L1622
- https://gitlab.com/samba-team/samba/-/blob/samba-4.24.3/nsswitch/pam_winbind.c#L1590
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.