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Fencer Vulns
high 7.8

CVE-2025-40104 json

ixgbevf: fix mailbox API compatibility by negotiating supported features

published 2025-10-30 12 mo ago modified 2026-10-19 20 d ago also EUVD-2025-36974

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

ixgbevf: fix mailbox API compatibility by negotiating supported features

There was backward compatibility in the terms of mailbox API. Various drivers from various OSes supporting 10G adapters from Intel portfolio could easily negotiate mailbox API.

This convention has been broken since introducing API 1.4. Commit 0062e7cc955e ("ixgbevf: add VF IPsec offload code") added support for IPSec which is specific only for the kernel ixgbe driver. None of the rest of the Intel 10G PF/VF drivers supports it. And actually lack of support was not included in the IPSec implementation - there were no such code paths. No possibility to negotiate support for the feature was introduced along with introduction of the feature itself.

Commit 339f28964147 ("ixgbevf: Add support for new mailbox communication between PF and VF") increasing API version to 1.5 did the same - it introduced code supported specifically by the PF ESX driver. It altered API version for the VF driver in the same time not touching the version defined for the PF ixgbe driver. It led to additional discrepancies, as the code provided within API 1.6 cannot be supported for Linux ixgbe driver as it causes crashes.

The issue was noticed some time ago and mitigated by Jake within the commit d0725312adf5 ("ixgbevf: stop attempting IPSEC offload on Mailbox API 1.5"). As a result we have regression for IPsec support and after increasing API to version 1.6 ixgbevf driver stopped to support ESX MBX.

To fix this mess add new mailbox op asking PF driver about supported features. Basing on a response determine whether to set support for IPSec and ESX-specific enhanced mailbox.

New mailbox op, for compatibility purposes, must be added within new API revision, as API version of OOT PF & VF drivers is already increased to 1.6 and doesn't incorporate features negotiate op.

Features negotiation mechanism gives possibility to be extended with new features when needed in the future.

Patch / fix

  • Linux Linux 6.1.158, 6.6.114, 6.12.55, 6.17.5, 6.18
  • linux Debian 12 6.1.158-1
  • linux Debian 13 6.12.57-1
  • linux Debian 14 6.17.6-1

debian advisories DEBIAN-CVE-2025-40104

  • linux Ubuntu 24.04 LTS 6.8.0-106.106
  • linux Ubuntu 25.10 6.17.0-14.14
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1050.53
  • linux-aws Ubuntu 25.10 6.17.0-1007.7
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1052.55
  • linux-gcp Ubuntu 25.10 6.17.0-1007.7
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1048.53
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1049.49

ubuntu advisories UBUNTU-CVE-2025-40104

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt Linux Micro 6.2 6.12.0-160000.7.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.7.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.7.1
  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.7.1
  • kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1.160000.2.4
  • kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.7.1
  • kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.7.1
  • kernel-kvmsmall SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.7.1

suse advisories SUSE-SU-2025:21080-1SUSE-SU-2025:21147-1SUSE-SU-2025:21180-1SUSE-SU-2026:20561-1SUSE-SU-2025:4141-1SUSE-SU-2025:4132-1

  • kernel-source-longterm openSUSE Tumbleweed 6.18.16-1.1
  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.7.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.7.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.7.1

opensuse advisories openSUSE-SU-2026:10301-1openSUSE-SU-2025:20091-1openSUSE-SU-2025:15702-1

  • kernel Azure Linux 3.0 6.6.117.1-1

azure linux advisories AZL-69400

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-40104 updated cvss 5.5

kernel: ixgbevf: fix mailbox API compatibility by negotiating supported features

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: no fix available, no fix planned “Will not fix”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
24 d ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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