Bug 2461759 (CVE-2026-31685) - CVE-2026-31685 kernel: netfilter: ip6t_eui64: reject invalid MAC header for all packets
Summary: CVE-2026-31685 kernel: netfilter: ip6t_eui64: reject invalid MAC header for a...
Keywords:
Status: NEW
Alias: CVE-2026-31685
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-04-25 09:01 UTC by OSIDB Bzimport
Modified: 2026-06-12 19:51 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:21556 0 None None None 2026-05-28 01:24:04 UTC
Red Hat Product Errata RHSA-2026:21557 0 None None None 2026-05-28 01:19:57 UTC
Red Hat Product Errata RHSA-2026:21706 0 None None None 2026-05-28 08:26:02 UTC
Red Hat Product Errata RHSA-2026:21745 0 None None None 2026-05-28 13:26:27 UTC
Red Hat Product Errata RHSA-2026:23224 0 None None None 2026-06-04 12:16:37 UTC
Red Hat Product Errata RHSA-2026:23237 0 None None None 2026-06-04 10:22:41 UTC
Red Hat Product Errata RHSA-2026:24343 0 None None None 2026-06-08 03:03:29 UTC
Red Hat Product Errata RHSA-2026:25095 0 None None None 2026-06-10 17:36:26 UTC
Red Hat Product Errata RHSA-2026:25533 0 None None None 2026-06-12 19:51:45 UTC

Description OSIDB Bzimport 2026-04-25 09:01:41 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netfilter: ip6t_eui64: reject invalid MAC header for all packets

`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address
and compares it with the low 64 bits of the IPv6 source address.

The existing guard only rejects an invalid MAC header when
`par->fragoff != 0`. For packets with `par->fragoff == 0`, `eui64_mt6()`
can still reach `eth_hdr(skb)` even when the MAC header is not valid.

Fix this by removing the `par->fragoff != 0` condition so that packets
with an invalid MAC header are rejected before accessing `eth_hdr(skb)`.
Comment 1 Alexander B 2026-04-27 10:24:39 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042545-CVE-2026-31685-3fcc@gregkh/T
Comment 3 errata-xmlrpc 2026-05-28 01:19:56 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:21557 https://access.redhat.com/errata/RHSA-2026:21557
Comment 4 errata-xmlrpc 2026-05-28 01:24:02 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:21556 https://access.redhat.com/errata/RHSA-2026:21556
Comment 5 errata-xmlrpc 2026-05-28 08:26:01 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:21706 https://access.redhat.com/errata/RHSA-2026:21706
Comment 6 errata-xmlrpc 2026-05-28 13:26:26 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:21745 https://access.redhat.com/errata/RHSA-2026:21745
Comment 7 errata-xmlrpc 2026-06-04 10:22:40 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:23237 https://access.redhat.com/errata/RHSA-2026:23237
Comment 8 errata-xmlrpc 2026-06-04 12:16:36 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:23224 https://access.redhat.com/errata/RHSA-2026:23224
Comment 9 errata-xmlrpc 2026-06-08 03:03:28 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:24343 https://access.redhat.com/errata/RHSA-2026:24343
Comment 10 errata-xmlrpc 2026-06-10 17:36:25 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:25095 https://access.redhat.com/errata/RHSA-2026:25095
Comment 11 errata-xmlrpc 2026-06-12 19:51:44 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

Via RHSA-2026:25533 https://access.redhat.com/errata/RHSA-2026:25533
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