CVE-2026-64086 Linux CVE debrief

Who should care

Linux kernel users and maintainers should review and apply the patch to prevent potential buffer overflow attacks. Affected operators, platforms, vulnerability-management, and security teams should also be aware of the vulnerability and take necessary actions.

Technical summary

The Linux kernel vulnerability CVE-2026-64086 was caused by an insufficient read buffer size in the adm1266_pmbus_block_xfer function. The buffer was declared as u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1], but the function setup was told to write up to 257 bytes (ADM1266_PMBUS_BLOCK_MAX + 2) into it. This could cause a buffer overflow when receiving a max-length block response with a PEC byte. The issue was resolved by increasing the read buffer size to ADM1266_PMBUS_BLOCK_MAX + 2.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the official patch for CVE-2026-64086
• Update Linux kernel to the latest version
• Monitor system logs for potential buffer overflow attacks
• 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 was published on 2026-07-19T16:17:49.300Z and has not been modified since then. The NVD entry is currently Received. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the official CVE record. The Linux kernel vulnerability CVE-2026-64086 was caused by an insufficient read buffer size in the adm1266_pmbus_block_xfer function. The buffer was declared as u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1], but the function setup was told to write up to 257 bytes (ADM1266_PMBUS_BLOCK_MAX + 2) into it.

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.