CVE-2026-89792 Linux CVE debrief

Who should care

Linux system administrators and users of ksmbd should verify their kernel versions and apply patches to prevent out-of-bounds reads in ksmbd share config responses. This includes reviewing system configurations for ksmbd usage, validating IPC share configuration payload sizes, and monitoring Linux kernel updates for potential future vulnerabilities. Additionally, defenders should review the supplied official advisory or CVE record to validate affected

Why it matters

CVE-2026-89792 is a Linux kernel vulnerability in ksmbd that allows for out-of-bounds reads in share config responses. Defenders should verify kernel versions, validate IPC share configuration payload sizes, and monitor Linux kernel updates to prevent potential exploitation.

• Verify Linux kernel versions to prevent potential out-of-bounds reads
• Validate IPC share configuration payload sizes to prevent ksmbd vulnerabilities
• Monitor Linux kernel updates for potential future vulnerabilities

Technical summary

The Linux kernel's ksmbd module had a vulnerability allowing out-of-bounds reads in share config responses. This was resolved by validating IPC share configuration payload sizes before consuming variable-length fields. The ksmbd module is responsible for handling SMB/CIFS requests in the Linux kernel. By validating IPC share configuration payload sizes, the vulnerability was addressed, preventing potential out-of-bounds reads that could have allowed attackers to access sensitive information or cause a denial-of-service condition.

Defensive priority

Verify Linux kernel versions and apply patches to prevent out-of-bounds reads in ksmbd share config responses.

Recommended defensive actions

• Verify Linux kernel versions and apply patches to prevent out-of-bounds reads in ksmbd share config responses
• Review system configurations for ksmbd usage and validate IPC share configuration payload sizes
• Monitor Linux kernel updates for potential future vulnerabilities
• 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. Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• [source tracking]

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but additional information on affected systems and exploitation is limited. The Linux kernel's ksmbd module had a vulnerability allowing out-of-bounds reads in share config responses. This was resolved by validating IPC share configuration payload sizes before consuming variable-length fields. However, specific details about the number of affected systems, potential exploits, or attack vectors are not publicly available. Defenders should verify kernel versions, review

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.