CVE-2026-80803 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel-based systems, particularly those with NFC functionality, should assess exposure and prioritize patching. They should also review system configurations for NFC functionality, monitor system logs for potential exploitation attempts, and implement compensating controls for exposed systems. Linux kernel version administrators and security teams should prioritize verifying and applying patches for affected versions.

Why it matters

CVE-2026-80803 is a vulnerability in the Linux kernel's NFC implementation that allows a nearby malicious NFC-F device to potentially overflow the stack-local struct nfc_target. Defenders should prioritize verifying and applying patches, assessing exposure, and monitoring system logs.

• Verify and prioritize patching for Linux kernel versions affected by this vulnerability
• Assess NFC functionality exposure and implement compensating controls if necessary
• Monitor system logs for potential exploitation attempts

Technical summary

The Linux kernel's NFC implementation does not properly validate the length of SENSF_RES responses from remote NFC-F devices, allowing for potential stack overflows. The issue is addressed through commits that clamp the response length to the destination buffer, preventing buffer overflows. This vulnerability affects Linux kernel versions and can be mitigated by verifying and applying patches, reviewing system configurations, and monitoring system logs for potential exploitation attempts. The vulnerability was found by 0sec automated security-research tooling.

Defensive priority

Defenders should prioritize verifying and applying patches for Linux kernel versions affected by this vulnerability, particularly for systems with NFC functionality.

Recommended defensive actions

• Verify and apply patches for Linux kernel versions affected by this vulnerability
• Review system configurations for NFC functionality and ensure it is properly secured
• Monitor system logs for potential exploitation attempts
• Assess exposure of Linux kernel-based systems with NFC functionality
• Implement compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions and retest remediated assets
• Review relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The vulnerability was found by 0sec automated security-research tooling. The issue is resolved in the Linux kernel through commits that clamp the SENSF_RES length to the destination buffer. The commits ensure that the length of the SENSF_RES response from a remote NFC-F device does not exceed the destination buffer, preventing potential stack overflows. Defenders should verify and apply patches for affected Linux kernel versions and review system configurations for NFC functionality.

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.