GHSA-6FMW-7W5G-3PF9
Vulnerability from github – Published: 2026-07-15 15:33 – Updated: 2026-07-15 15:33A 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": [],
"aliases": [
"CVE-2026-15779"
],
"database_specific": {
"cwe_ids": [
"CWE-732"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-15T13:17:03Z",
"severity": "MODERATE"
},
"details": "A flaw was found in samba\u0027s pam_winbind. When mkhomedir is enabled, pam_winbind chowns the target account\u0027s 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.",
"id": "GHSA-6fmw-7w5g-3pf9",
"modified": "2026-07-15T15:33:03Z",
"published": "2026-07-15T15:33:03Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-15779"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-15779"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2499991"
},
{
"type": "WEB",
"url": "https://gitlab.com/samba-team/samba/-/blob/samba-4.19.4/nsswitch/pam_winbind.c"
},
{
"type": "WEB",
"url": "https://gitlab.com/samba-team/samba/-/blob/samba-4.23.5/nsswitch/pam_winbind.c#L1622"
},
{
"type": "WEB",
"url": "https://gitlab.com/samba-team/samba/-/blob/samba-4.24.3/nsswitch/pam_winbind.c#L1590"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H",
"type": "CVSS_V3"
}
]
}
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