Vulnerability in Red Hat Enterprise Linux 10
CVE-2026-15779
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H.
EPSS exploit prediction
EPSS: 0.001 (1.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 1.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000
Affected products
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-15779 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
- gitlab.com/samba-team/samba/-/blob/samba-4.19.4/nsswitch/pam_winbind.c
- gitlab.com/samba-team/samba/-/blob/samba-4.23.5/nsswitch/pam_winbind.c
- gitlab.com/samba-team/samba/-/blob/samba-4.24.3/nsswitch/pam_winbind.c
Frequently asked questions
- What is CVE-2026-15779?
- CVE-2026-15779 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 6.1/10. Published 2026-07-15.
- How severe is CVE-2026-15779?
- Medium severity. CVSS v3 base score is 6.1 out of 10.