CVE-2026-93812 Linux CVE debrief

Who should care

Linux kernel maintainers and users, particularly those responsible for managing and securing Linux kernel-based systems, should assess exposure and verify patch deployment to prevent potential denial-of-service attacks. This includes reviewing Linux kernel patch deployment for the ksmbd module, updating the Linux kernel to the latest version, and verifying patch deployment to prevent memory leaks.

Why it matters

A memory leak vulnerability was found in the Linux kernel's ksmbd module. Linux kernel maintainers and users should assess exposure and verify patch deployment to prevent potential denial-of-service attacks.

• Verify patch deployment to prevent memory leaks
• Assess exposure to potential denial-of-service attacks
• Update Linux kernel to the latest version to ensure security

Technical summary

The ndr_encode_v4_ntacl() function in the Linux kernel's ksmbd module allocates memory for sd_ndr.data but fails to free it in case of subsequent errors during encoding. This issue has been resolved by moving the kfree(sd_ndr.data) call to the out label to ensure the buffer is released on all success and error return paths. The fix ensures that the memory allocated for sd_ndr.data is properly released, preventing a memory leak vulnerability. Linux kernel maintainers and users should assess exposure and verify patch deployment to prevent potential denial-of-service attacks.

Defensive priority

Linux kernel maintainers and users should assess exposure and verify patch deployment.

Recommended defensive actions

• Review Linux kernel patch deployment for ksmbd module
• Assess exposure and verify patch deployment
• Update Linux kernel to the latest version
• Verify patch deployment to prevent memory leaks
• Assess exposure to potential denial-of-service attacks
• Review compensating controls for exposed systems
• Track exceptions and retest remediated assets

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. Three source references from the Linux kernel Git repository are available. The vulnerability was found in the Linux kernel's ksmbd module, which is responsible for handling SMBv3 requests. The ndr_encode_v4_ntacl() function allocates memory for sd_ndr.data but fails to free it in case of subsequent errors during encoding. This issue has been resolved by moving the kfree(sd_ndr.data) call to the out label to ensure the buffer is released on all success and error return

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.