CVE-2026-98114 Linux CVE debrief

Who should care

Linux kernel administrators and security teams should assess exposure and prioritize patching in environments where ksmbd is used. They should verify Linux kernel versions and ksmbd configurations to ensure proper security descriptor handling. This includes reviewing and updating ACL configurations for ksmbd and monitoring Linux kernel updates and security advisories for further information on this vulnerability.

Why it matters

Defenders should prioritize verifying and applying patches for Linux kernel versions affected by this vulnerability, particularly in environments where ksmbd is used, as it can lead to incomplete ACL conversions and potential security issues.

• Verification of Linux kernel versions and ksmbd configurations is necessary to ensure proper security descriptor handling.
• Incomplete ACL conversions can lead to unintended access control behavior.

Technical summary

The Linux kernel's ksmbd module had a vulnerability where DACL parsing errors were silently accepted, allowing for incomplete ACL conversions. This has been fixed by propagating parsing and allocation errors. The vulnerability affects Linux kernel versions and can be mitigated by applying patches. Administrators should assess exposure and prioritize patching in environments where ksmbd is used. The fix ensures that malformed security descriptors are rejected before inode attributes or ACL xattrs are updated, preventing potential security issues.

Defensive priority

Defenders should prioritize verifying and applying patches for Linux kernel versions affected by this vulnerability, particularly in environments where ksmbd is used.

Recommended defensive actions

• Verify and apply patches for Linux kernel versions affected by this vulnerability
• Review and update ACL configurations for ksmbd to ensure proper security descriptor handling
• Monitor Linux kernel updates and security advisories for further information on this vulnerability
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• 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

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description and affected components. However, specific version information and exploitation details are not provided. Defenders should verify Linux kernel versions and ksmbd configurations to ensure proper security descriptor handling. The CVE Program record and NVD detail page offer source-provided CVE metadata and official vulnerability assessment.

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.