CVE-2026-15779

Aliases:UBUNTU-CVE-2026-15779DEBIAN-CVE-2026-15779
Advisory lineage Upstream: 0 Downstream: 14
Deferred
Published: 15 Jul 2026, 12:33
Last modified:15 Jul 2026, 13:04

Vulnerability Summary

Overall Risk (default)
low
24/100
CVSS Score
6.1 MEDIUM
v3.1 (cve.org)
EPSS Score
0.1% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

15 Jul 2026, 12:33
Published
Vulnerability first disclosed
15 Jul 2026, 13:04
Last Modified
Vulnerability information updated

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 Metrics

  • v3.1•MEDIUM•Score: 6.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

EPSS Trends

Current EPSS score: 0.10%• Percentile: 1%

Techniques & Countermeasures

  • CWE-732•Incorrect Permission Assignment for Critical Resource

    The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

Affected Systems

  • debian•samba

    all | all | all | all

  • ubuntu•samba

    all | < 2:4.15.13+dfsg-0ubuntu1.13 | < 2:4.19.5+dfsg-4ubuntu9.7 | < 2:4.23.6+dfsg-1ubuntu2.2

References (9)