CVE-2026-64393
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: run set info with opener credentials
SMB2 SET_INFO handlers call path-based VFS helpers after checking the
access mask granted to the SMB handle. Those helpers perform their owner,
inode permission and LSM checks using the current ksmbd worker credentials.
Run the complete SET_INFO dispatch with the credentials captured when the
handle was opened. This also removes the separate security information
credential setup and keeps all SET_INFO classes under one credential scope.
Direct override_creds() is used because it can nest with the request
credential overrides already used by rename and link helpers.
CSIRTS triage
- What
- The ksmbd service runs set info with opener credentials, which may lead to vulnerabilities.
- Who is affected
- Deployments of the ksmbd service are affected.
- Urgency
- Remediation is necessary to prevent potential exploitation, although exploitation status is currently unknown.
- Action
- Update to the latest version of the ksmbd service.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.48% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 39% of all EPSS-scored CVEs.
Advisory coverage (2)
- highCVE-2026-64393: ksmbd: run set info with opener credentialsmsrc · 2026-08-06
- criticalCVE-2026-64393: In the Linux kernel, the following vulnerability has been resolved: ksmbd: run set info with o…nvd · 2026-07-25
External references
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