Description
A flaw was found in SSSD's NFS idmap plugin. When retrieving cached user or group names, the plugin detects if an entry exceeds the destination buffer size but fails to abort before copying data. A local attacker can trigger this vulnerability by requesting identity lookups that resolve to oversized cached entries, resulting in an out-of-bounds write. This flaw primarily leads to a Denial of Service (DoS) by crashing the identity mapping service, and may also corrupt adjacent process memory.
Published: 2026-10-06
Score: 5.8 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
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Remediation

Vendor Workaround

Disable the vulnerable memcache lookup path of the SSSD NFS idmap plugin: in the rpc.idmapd configuration, set `memcache = false` for the SSSD plugin (or switch the translation `Method` away from `sss`), and restart the rpc.idmapd service to apply the change. This makes uid/gid name lookups bypass the vulnerable get_user_from_mc() and get_group_from_mc() code paths. Note that with memcache disabled, lookups are served through the SSSD responder instead of the in-memory cache, which may add lookup latency on systems with heavy NFS identity resolution traffic. No released package fix is currently established for this issue, so this configuration change is the recommended interim workaround until a fixed build is available.

Tracking

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History

Tue, 06 Oct 2026 21:15:00 +0000

Type Values Removed Values Added
First Time appeared Redhat openshift Container Platform
Sssd
Sssd sssd
Vendors & Products Redhat openshift Container Platform
Sssd
Sssd sssd

Tue, 06 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 06 Oct 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 06 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
Description A flaw was found in SSSD's NFS idmap plugin. When retrieving cached user or group names, the plugin detects if an entry exceeds the destination buffer size but fails to abort before copying data. A local attacker can trigger this vulnerability by requesting identity lookups that resolve to oversized cached entries, resulting in an out-of-bounds write. This flaw primarily leads to a Denial of Service (DoS) by crashing the identity mapping service, and may also corrupt adjacent process memory.
Title Sssd: sssd: denial of service via out-of-bounds write in nfs idmap plugin
First Time appeared Redhat
Redhat enterprise Linux
Redhat openshift
Weaknesses CWE-787
CPEs cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat openshift
References
Metrics cvssV3_1

{'score': 5.8, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H'}


Subscriptions

Redhat Enterprise Linux Openshift Openshift Container Platform
Sssd Sssd
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-10-16T10:57:37.848Z

Reserved: 2026-10-01T17:22:16.764Z

Link: CVE-2026-104036

cve-icon Vulnrichment

Updated: 2026-10-06T13:01:18.533Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-06T01:16:34.567

Modified: 2026-10-06T15:09:20.387

Link: CVE-2026-104036

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-05T23:47:56Z

Links: CVE-2026-104036 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-06T20:56:20Z

Weaknesses