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CVE-2026-64047 Linux CVE debrief

A Linux kernel vulnerability, CVE-2026-64047, was resolved by addressing an off-by-one error in sg_chain entry count for wrapped sk_msg ring. The issue arose in tls_push_record() when chaining the tail portion of the ring to the head using sg_chain(). This vulnerability affects Linux kernel versions and has been resolved by converting to ARRAY_SIZE and dropping the data[start] / - start calculation.

Vendor
Linux
Product
Unknown
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-19
Original CVE updated
2026-07-19
Advisory published
2026-07-19
Advisory updated
2026-07-19

Who should care

Linux kernel maintainers, Linux distribution vendors, and users of Linux kernel versions affected by this vulnerability should be aware of this issue and take necessary actions to update their kernels. This includes reviewing and applying patches from Linux kernel maintainers, monitoring Linux kernel updates and security advisories, and tracking exceptions and retesting remediated assets.

Technical summary

The Linux kernel vulnerability CVE-2026-64047 was caused by an off-by-one error in sg_chain entry count for wrapped sk_msg ring. The sg_chain() function was called with an incorrect ring size, leading to the chain pointer being placed at an incorrect position. This issue was resolved by converting to ARRAY_SIZE and dropping the data[start] / - start calculation. The affected product context is Linux kernel versions, and the defensive impact is related to updating Linux kernel to the latest version.

Defensive priority

Medium

Recommended defensive actions

  • Update Linux kernel to the latest version
  • Review and apply patches from Linux kernel maintainers
  • Monitor Linux kernel updates and security advisories
  • 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 2026-07-19T16:17:45.053Z and has not been modified since then. The NVD entry is currently Received. There is limited information available about this vulnerability, and defenders should verify the affected scope and severity with the official advisory or CVE record.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-19T16:17:45.053Z and has not been modified since then.