CVE-2026-64132
Received Received - Intake

Use-After-Free in Linux Kernel IPv6 IOAM

Publication date: 2026-07-19

Last updated on: 2026-07-19

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: ioam: refresh hdr pointer before ioam6_event() Reported by Sashiko: In ipv6_hop_ioam(), the hdr pointer is initialized to point into the skb's linear data buffer. Later, the code calls skb_ensure_writable(), which might reallocate the buffer: if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len)) goto drop; /* Trace pointer may have changed */ trace = (struct ioam6_trace_hdr *)(skb_network_header(skb) + optoff + sizeof(*hdr)); ioam6_fill_trace_data(skb, ns, trace, true); ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev), GFP_ATOMIC, (void *)trace, hdr->opt_len - 2); If the skb is cloned or lacks sufficient linear headroom, skb_ensure_writable() will invoke pskb_expand_head(), which reallocates the skb's data buffer and frees the old one, invalidating pointers to it. While the code recalculates the trace pointer immediately after the call to skb_ensure_writable(), it fails to recalculate the hdr pointer. This patch fixes the above by recalculating the hdr pointer before passing hdr->opt_len to ioam6_event(), so that we avoid any UaF.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-07-19
Last Modified
2026-07-19
Generated
2026-07-20
AI Q&A
2026-07-19
EPSS Evaluated
N/A
NVD
CVE-2026-64132
EUVD
EUVD-2026-45817

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability is in the Linux kernel's IPv6 IOAM (In-situ Operations, Administration, and Maintenance) feature. It involves a use-after-free (UaF) issue where a pointer to a data structure becomes invalid after memory reallocation. The hdr pointer is not refreshed after skb_ensure_writable() potentially reallocates the skb buffer, leading to a dangling pointer.

Detection Guidance

This vulnerability is specific to the Linux kernel's IPv6 IOAM implementation and may not have direct detection commands. Monitor kernel logs for crashes or warnings related to IPv6 IOAM processing. Check for kernel updates addressing this issue.

Impact Analysis

This vulnerability could allow an attacker to cause a denial-of-service (DoS) condition or potentially execute arbitrary code with kernel privileges. It may lead to system crashes, data corruption, or unauthorized access if exploited.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA as it is a Linux kernel memory safety issue in IPv6 IOAM functionality. Compliance impacts would depend on system configuration and use of affected features.

Mitigation Strategies

Update the Linux kernel to the latest stable version that includes the patch for this vulnerability. Monitor vendor advisories for kernel updates and apply them promptly to prevent potential use-after-free issues in IPv6 IOAM handling.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-64132. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart