CVE-2026-64087 Linux CVE debrief

Who should care

Users of the Linux kernel, particularly those using the hwmon: (pmbus/adm1266) module, should be aware of this vulnerability and ensure they are running the patched version. This vulnerability could lead to an out-of-bounds read if a device reports a record_count greater than 32.

Technical summary

The vulnerability exists in the adm1266_nvmem_read_blackbox() function, where the record_count is taken directly from the BLACKBOX_INFO response. If the record_count exceeds 32, it could lead to an out-of-bounds read. The patch introduces a cap at ADM1266_BLACKBOX_MAX_RECORDS (32) and returns -EIO for larger values. This fix prevents a malformed BLACKBOX_INFO response from driving the loop out of bounds.

Defensive priority

Medium

Recommended defensive actions

• Inventory and verify Linux kernel versions
• Apply patches for hwmon: (pmbus/adm1266) module
• Monitor for unusual activity in kernel logs
• 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 2026-07-19T16:17:49.433Z 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 advisory. The Linux kernel patch for hwmon: (pmbus/adm1266) rejects implausible blackbox record_count, which could lead to an out-of-bounds read if a device reports a record_count greater than 32.

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.