CVE-2026-89703

What is known

In the Linux kernel, the following vulnerability has been resolved: nfsd: set SC_STATUS_FREED in nfsd4_drop_revoked_stid for delegations nfsd4_drop_revoked_stid() handles FREE_STATEID for admin-revoked delegations but does not set SC_STATUS_FREED before releasing cl_lock. revoke_delegation() uses this flag to detect whether FREE_STATEID has already processed the delegation -- without it, the freed delegation is added to cl_revoked via list_add(), producing a use-after-free when cl_revoked is later traversed in __destroy_client(). The SC_STATUS_REVOKED path in nfsd4_free_stateid() (line 7983) already sets SC_STATUS_FREED correctly. Apply the same pattern to the SC_STATUS_ADMIN_REVOKED path in nfsd4_drop_revoked_stid().

Business impact

Successful exploitation of CVE-2026-89703, a critical vulnerability (CVSS 9.8) affecting the affected product, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether the affected product is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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