CVE-2026-64501 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel maintenance, SPI transfer handling, and bus lock management should assess exposure and prioritize patching and monitoring. Additionally, operators and security teams managing affected systems should review compensating controls and implement monitoring to detect potential issues. Affected vendors should review and adjust SPI transfer and bus lock handling to prevent unintended behavior.

Why it matters

A high-severity vulnerability in the Linux kernel's iio: adc: ad_sigma_delta driver can cause chip select (CS) to be held asserted and lead to state leaks, potentially allowing for unintended SPI transfers. Defenders should prioritize verifying and applying patches, reviewing SPI transfer and bus lock handling, and monitoring for potential issues.

• Verify and apply patches to prevent potential issues with the ad_sigma_delta driver
• Review and adjust SPI transfer and bus lock handling to prevent unintended behavior

Technical summary

The vulnerability in the Linux kernel's iio: adc: ad_sigma_delta driver causes the chip select (CS) to be held asserted and leads to state leaks. This can potentially allow for unintended SPI transfers. The issue has been resolved through patches provided in the source references. The vulnerability was found in the ad_sigma_delta_single_conversion() and ad_sd_buffer_postenable() functions, where improper handling of the CS and bus lock led to potential security risks. The issue was resolved by moving set_mode(AD_SD_MODE_IDLE) and disable_one() calls into the out_unlock: block, after keep_cs_asserted is cleared, and by clearing keep_cs_asserted first, then calling set_mode(AD_SD_MODE_IDLE) to revert the device

Defensive priority

Defenders should prioritize verifying and applying patches for affected Linux kernel versions, reviewing SPI transfer and bus lock handling, and monitoring for potential issues with the ad_sigma_delta driver.

Recommended defensive actions

• Verify and apply patches for affected Linux kernel versions
• Review SPI transfer and bus lock handling in the ad_sigma_delta driver
• Monitor for potential issues with the ad_sigma_delta driver
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and source metadata indicate a high-severity vulnerability in the Linux kernel's iio: adc: ad_sigma_delta driver. The issue has been resolved through patches provided in the source references.

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.