Medium [CVE-2026-89682] NFS daemon (nfsd) use-after-free vulnerability in file cache disposal
This medium-severity Red Hat Linux advisory covers CVE-2026-89682 affecting Red Hat OpenShift Container Platform 4.
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Summary
A flaw was found in the Linux kernel's NFS daemon (nfsd) component. The nfsd_file_dispose_list_delayed() function, responsible for deferring file disposal, uses a separately allocated structure for its freeme queue.
During network namespace teardown, this structure can be prematurely freed. This allows other kernel callbacks to attempt to dereference the freed memory, leading to a use-after-free (UAF) vulnerability.
A local attacker could potentially exploit this to cause a system crash or escalate privileges. Red Hat severity: Important — CVSS 6.6 (CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H).
Weakness: CWE-825. Affected Red Hat products: Red Hat OpenShift Container Platform 4.
Red Hat does not currently list a fixing RHSA for this CVE.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
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