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Vulnerability · Published Jul 15, 2026 · Assigned by redhat

CVE-2026-15779Samba-winbind: samba: pam_winbind mkhomedir chowns critical system paths without validation

Medium 6.1

In plain English

A medium-severity incorrect permission assignment in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium
Exploit odds (30 days)0.1%top 95.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12sambano fix listedDEBIAN-CVE-2026-15779
Debian:13sambano fix listedDEBIAN-CVE-2026-15779
Debian:14sambano fix listedDEBIAN-CVE-2026-15779
Ubuntu:22.04:LTSsamba2:4.15.13+dfsg-0ubuntu1.13UBUNTU-CVE-2026-15779
Ubuntu:24.04:LTSsamba2:4.19.5+dfsg-4ubuntu9.7UBUNTU-CVE-2026-15779
Ubuntu:26.04:LTSsamba2:4.23.6+dfsg-1ubuntu2.2UBUNTU-CVE-2026-15779

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 6 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 9 see references

Weakness: CWE-732 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

References