CVE-2026-64132

Critical

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.

Package Linux Kernel
Published 2026-07-19
Last modified 2026-08-13
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

9.8

out of 10
Critical
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-416

CVE-2026-64132 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.9 and later are affected. Fixed in 6.12.92, 6.18.34, 7.0.11, 7.1 and their respective stable series.

Affected from
≥ 6.9
Fixed in
✓ 6.12.92 6.12.x ✓ 6.18.34 6.18.x ✓ 7.0.11 7.0.x ✓ 7.1

References

4 total

Frequently asked questions

  • What is CVE-2026-64132?

    CVE-2026-64132 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 6.9 onward and has been patched in 6.12.92, 6.18.34, 7.0.11 and others. CVE-2026-64132 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-64132?

    CVE-2026-64132 has a CVSS score of 9.8 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-64132?

    Yes. CVE-2026-64132 has been patched. Fixed versions include 6.12.92, 6.18.34, 7.0.11 and others. If you are running Linux kernel 6.9 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-64132 actively exploited?

    No. CVE-2026-64132 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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