CVE-2026-64327 Linux CVE debrief

Who should care

Linux kernel developers, administrators, and users who need to verify and apply patches for Linux kernel versions 6.9, 6.13, 6.19, 7.2 rc1, and 7.2 rc2. These individuals should assess exposure in Linux kernel deployments, inventory Linux kernel versions for potential exposure, and apply patches as needed.

Why it matters

CVE-2026-64327 is a Linux kernel vulnerability that could lead to incorrect DMA directions due to inaccurate endpoint direction checks. Defenders should verify and apply patches for affected Linux kernel versions, assess exposure in Linux kernel deployments, and inventory Linux kernel versions for potential exposure.

• Verify endpoint direction checks for Linux kernel versions 6.9, 6.13, 6.19, 7.2 rc1, and 7.2 rc2
• Assess exposure in Linux kernel deployments
• Apply patches for Linux kernel versions 6.9, 6.13, 6.19, 7.2 rc1, and 7.2 rc2

Technical summary

The Linux kernel vulnerability (CVE-2026-64327) is related to the usb gadget f_fs component, where the epfile->in was not initialized early, leading to incorrect endpoint direction checks. This issue affects Linux kernel versions 6.9, 6.13, 6.19, 7.2 rc1, and 7.2 rc2. Defenders should verify and apply patches for affected Linux kernel versions, assess exposure in Linux kernel deployments, and inventory Linux kernel versions for potential exposure. The vulnerability has been resolved by moving the initialization to ffs_epfiles_create(), ensuring epfile->in is accurate before userspace opens the endpoint files.

Defensive priority

Verify and apply patches for Linux kernel versions 6.9, 6.13, 6.19, 7.2 rc1, and 7.2 rc2; assess exposure in Linux kernel deployments.

Recommended defensive actions

• Verify Linux kernel version and apply patches for versions 6.9, 6.13, 6.19, 7.2 rc1, and 7.2 rc2
• Assess exposure in Linux kernel deployments
• Inventory Linux kernel versions for potential exposure
• 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 and NVD vulnerability detail provide information on the vulnerability, its CVSS score, and affected Linux kernel versions. The vulnerability has been resolved in Linux kernel versions 6.9, 6.13, 6.19, 7.2 rc1, and 7.2 rc2. Defenders should verify endpoint direction checks for these versions, assess exposure in Linux kernel deployments, and apply patches as needed. The source detail is limited, so defenders should exercise caution when verifying and applying patches.

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.