CVE-2026-43186

CVE-2026-43186 · ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()

CVSS 9.8 · Critical · EPSS 0.6% · Fix available

dpkg-query -W -f='${source:Package} ${binary:Package} ${Version}\n' | awk '$1=="linux"'

curl -fsSL https://patchfirst.dev/check.sh | sh

This page contains facts from public vulnerability sources. Check the original advisory before updating.

This page shows selected source facts. See the linked advisories for the complete description and affected versions.

In the Linux kernel, the following vulnerability has been resolved: ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data() On the receive path, __ioam6_fill_trace_data() uses trace->nodelen to decide how much data to write for each node. It trusts this field as-is from the incoming packet, with no consistency check against trace->type (the 24-bit field that tells which data items are present). A crafted packet can set nodelen=0 while setting type bits 0-21, causing the function to write ~100 bytes past the allocated region (into skb_shared_info), which corrupts adjacent heap memory and leads to a kernel panic. Add a shared helper ioam6_trace_compute_nodelen() in ioam6.c to derive the expected nodelen from the type field, and use it: - in ioam6_iptunnel.c (send path, existing validation) to replace the open-coded computation; - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose nodelen is inconsistent with the type field, before any data is written. Per RFC 9197, bits 12-21 are each short (4-octet) fields, so they are included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to 0xff1ffc00).

Published

2026-05-06T11:27:57.053Z

Updated

2026-10-19T19:16:23.065Z

Stack: system

Check your server →