From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-72348: netfilter: ip6tables: mark malformed IPv6 extension headers for hotdrop
Date: Sat, 15 Aug 2026 15:07:07 +0900 [thread overview]
Message-ID: <2026081511-CVE-2026-72348-e6e6@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ip6tables: mark malformed IPv6 extension headers for hotdrop
The ah, hbh and rt matches check that the fixed extension header is
present, then use the header length field to derive the advertised
extension header length for matching.
For the ah match, add the missing advertised-length check. For hbh
and rt, update the existing advertised-length checks. In all three
cases, set hotdrop to true before returning false when the advertised
extension header length exceeds the available skb data.
Returning false treats the packet as a rule mismatch. Set hotdrop to
true and drop malformed packets so they cannot bypass rules intended
to drop packets with these IPv6 extension headers.
The Linux kernel CVE team has assigned CVE-2026-72348 to this issue.
Affected and fixed versions
===========================
Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 5.10.261 with commit f16d856b6af5fd0e7cb0b0212f70825b599ef72e
Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 5.15.212 with commit fc416870100cf16d5b9495199355a679c3a02d48
Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.1.178 with commit f775fcf384b06f35b612f78fa5601fee99eb6513
Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.6.145 with commit 2fd89a50a9783eed8ed23866b11c8b3d8779a7a8
Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.12.97 with commit 3578b6d92a5b1e603ae6e8c8f5538a709f03aba4
Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.18.40 with commit 3d441be2b1c5e98167302fa1c7b61960a067b112
Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 7.1.5 with commit d5e39e5eb6b30bc4a3bb7aba54c293cf36a806c7
Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 7.2-rc3 with commit 43ccc20b5a733226417832cf16ef45322e594990
Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.
Unaffected versions might change over time as fixes are backported to
older supported kernel versions. The official CVE entry at
https://cve.org/CVERecord/?id=CVE-2026-72348
will be updated if fixes are backported, please check that for the most
up to date information about this issue.
Affected files
==============
The file(s) affected by this issue are:
net/ipv6/netfilter/ip6t_ah.c
net/ipv6/netfilter/ip6t_hbh.c
net/ipv6/netfilter/ip6t_rt.c
Mitigation
==========
The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes. Individual
changes are never tested alone, but rather are part of a larger kernel
release. Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all. If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
https://git.kernel.org/stable/c/f16d856b6af5fd0e7cb0b0212f70825b599ef72e
https://git.kernel.org/stable/c/fc416870100cf16d5b9495199355a679c3a02d48
https://git.kernel.org/stable/c/f775fcf384b06f35b612f78fa5601fee99eb6513
https://git.kernel.org/stable/c/2fd89a50a9783eed8ed23866b11c8b3d8779a7a8
https://git.kernel.org/stable/c/3578b6d92a5b1e603ae6e8c8f5538a709f03aba4
https://git.kernel.org/stable/c/3d441be2b1c5e98167302fa1c7b61960a067b112
https://git.kernel.org/stable/c/d5e39e5eb6b30bc4a3bb7aba54c293cf36a806c7
https://git.kernel.org/stable/c/43ccc20b5a733226417832cf16ef45322e594990
reply other threads:[~2026-08-15 6:23 UTC|newest]
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