CVE-2026-89098 Red Hat CVE debrief

Who should care

System administrators and security teams responsible for Red Hat Enterprise Linux and OpenShift Container Platform systems using nfs-utils should assess exposure and prioritize patching to prevent potential local denial of service attacks.

Why it matters

CVE-2026-89098 is a medium-severity vulnerability in nfs-utils that can cause a Denial of Service via assertion failure in fsidd. Local users can exploit this by sending malformed requests. System administrators and security teams should assess exposure, prioritize patching for affected Red Hat Enterprise Linux and OpenShift Container Platform systems, and monitor for local threat activity.

• Denial of Service for filesystem identifier lookup services
• Potential disruption to local system operations
• Need for verification of affected versions and systems
• Prioritization of patching and remediation efforts

Technical summary

The fsidd daemon in nfs-utils improperly handles input over its local domain socket, relying on program assertions to verify command arguments. A local user can send a malformed request lacking required arguments to trigger an assertion failure, causing the daemon to crash and disrupting filesystem identifier lookup services until restarted. The vulnerability affects nfs-utils and can be triggered by a local user. The daemon's improper handling of input received over its local domain socket can be exploited to cause a Denial of Service.

Defensive priority

Assess exposure and prioritize patching for systems using nfs-utils, especially in local threat contexts.

Recommended defensive actions

• Inventory and assess nfs-utils usage in your environment.
• Prioritize patching for affected Red Hat Enterprise Linux and OpenShift Container Platform systems.
• Monitor for local threat activity and potential exploitation attempts.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE and NVD records provide details on the vulnerability and its impact. Red Hat has an advisory for this issue. The fsidd daemon in nfs-utils improperly handles input received over its local domain socket by relying on program assertions to verify command arguments. A local user can exploit this vulnerability by sending a malformed request lacking the required arguments to trigger an assertion failure. This causes the daemon to crash, resulting in a Denial of Service (DoS) for filesystem identifier lookup services until restarted

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.