CVE-2026-98125 Linux CVE debrief

Who should care

Linux kernel administrators and developers, CIFS mount users, and those responsible for maintaining Linux systems should assess exposure and prioritize patching. This includes reviewing the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.

Why it matters

CVE-2026-98125 is a Linux kernel vulnerability that allows clients to return stale data after insert/collapse range operations. Linux kernel administrators and developers, CIFS mount users, and those responsible for maintaining Linux systems should assess exposure and prioritize patching.

• Data integrity may be compromised due to stale data being returned after insert/collapse range operations
• Linux kernel deployments require assessment for exposure
• Patching affected systems is a priority

Technical summary

The Linux kernel vulnerability CVE-2026-98125 occurs in the smb/client implementation, specifically in the smb3_insert_range and smb3_collapse_range functions, which use truncate_pagecache_range to invalidate the affected page cache. However, if the offset or old EOF is not page-aligned, the boundary pages are only partially zeroed and remain uptodate, allowing clients to return stale data after a successful insert/collapse range operation.

Defensive priority

Assess Linux kernel deployments for exposure, prioritize patching for affected systems.

Recommended defensive actions

• Assess Linux kernel deployments for exposure
• Prioritize patching for affected systems
• Verify page cache invalidation in Linux kernel implementations
• 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 record and Linux kernel source code indicate a vulnerability in the smb/client implementation, specifically in the smb3_insert_range and smb3_collapse_range functions. The vulnerability allows clients to return stale data after a successful insert/collapse range operation due to partial page cache invalidation. Evidence is limited to the supplied CVE record and Linux kernel source code.

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.