CVE-2026-104045

A flaw was found in SSSD. A local user can trigger a Denial of Service (DoS) by exploiting a race condition in the autofs responder between asynchronous enumeration completion and map invalidation. By repeatedly sending concurrent map enumeration and invalidation requests, an attacker can cause memory to leak, leading to excessive memory consumption that can disrupt or crash the autofs service.

This vulnerability is rated as Moderate impact for Red Hat Enterprise Linux because exploitation is limited to a local denial of service against the SSSD autofs responder and requires winning a race condition under sustained concurrent requests. In typical Red Hat deployments, the autofs responder is only active when SSSD is explicitly configured to manage automount maps. Successful exploitation does not compromise system integrity or confidentiality, and the disruption remains isolated to the autofs responder daemon.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

A real workaround exists: disable the SSSD autofs responder on systems where automount map integration via SSSD is not required.

1. Stop and mask the SSSD autofs socket and service:

systemctl stop sssd-autofs.socket sssd-autofs.service

systemctl mask sssd-autofs.socket sssd-autofs.service

2. If the 'services' line in /etc/sssd/sssd.conf explicitly lists 'autofs', remove 'autofs' from the comma-separated list and restart SSSD:

systemctl restart sssd

Caveats: disabling the autofs responder prevents SSSD from serving automount maps, which will disrupt automated mounting of shares or user directories managed via SSSD. Restarting the SSSD service will briefly interrupt active authentication and directory lookup operations on the system.

Where the autofs responder must remain enabled, restricting local access to the responder to trusted users, where deployment policy permits, and avoiding repeated map invalidation and enumeration cycles against large maps can reduce exposure. No released package fix is currently established for this issue.