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PatchSiren cyber security CVE debrief

CVE-2026-64132 Linux CVE debrief

A use-after-free vulnerability was found in the Linux kernel's IPv6 IOAM (In-Situ OAM) implementation. The issue arises from the failure to refresh the hdr pointer after skb_ensure_writable() is called, which may reallocate the skb's data buffer and invalidate existing pointers. This vulnerability can lead to a use-after-free condition when hdr->opt_len is passed to ioam6_event(). The affected product is the Linux kernel, and the vulnerability class is a use-after-free condition. The likely operational impact is a potential denial-of-service or code execution.

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 developers and maintainers, network administrators, and security teams responsible for Linux-based systems should be aware of this vulnerability. They should review the official advisory and apply the provided patch to mitigate the vulnerability. Additionally, they should monitor for any suspicious activity related to IPv6 IOAM.

Technical summary

The vulnerability exists in the ipv6_hop_ioam() function, where the hdr pointer is initialized to point into the skb's linear data buffer. After calling skb_ensure_writable(), which may reallocate the buffer, the code fails to recalculate the hdr pointer. This can lead to a use-after-free condition when hdr->opt_len is passed to ioam6_event(). The affected product context is the Linux kernel's IPv6 IOAM implementation. The defensive impact is a potential denial-of-service or code execution.

Defensive priority

Medium

Recommended defensive actions

  • Review and apply the provided patch to the Linux kernel
  • Ensure that the Linux kernel is updated with the latest security patches
  • Monitor for any suspicious activity related to IPv6 IOAM
  • 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 2026-07-19T16:17:55.000Z 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's IPv6 IOAM implementation is vulnerable to a use-after-free condition. The official CVE record and NVD detail page provide additional context.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-19T16:17:55.000Z and has not been modified since then.