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Fencer Vulns
high 7.8

CVE-2026-31678 json

openvswitch: defer tunnel netdev_put to RCU release

published 2026-04-25 6 mo ago modified 2026-10-30 10 d ago also EUVD-2026-25645

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

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

openvswitch: defer tunnel netdev_put to RCU release

ovs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already detached the device. Dropping the netdev reference in destroy can race with concurrent readers that still observe vport->dev.

Do not release vport->dev in ovs_netdev_tunnel_destroy(). Instead, let vport_netdev_free() drop the reference from the RCU callback, matching the non-tunnel destroy path and avoiding additional synchronization under RTNL.

Patch / fix

  • Linux Linux 5.15.224, 6.1.168, 6.6.131, 6.12.80, 6.18.21, 6.19.11, 7.0
  • linux Debian 12 6.1.170-1
  • linux Debian 13 6.12.85-1
  • linux Debian 14 6.19.11-1

debian advisories DEBIAN-CVE-2026-31678

  • linux Ubuntu 24.04 LTS 6.8.0-136.136
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1061.64
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1064.72
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1059.67
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1061.62
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1063.71
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1046.50
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1061.65

ubuntu advisories UBUNTU-CVE-2026-31678

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 RHEL 10.2 6.12.0-211.67.1.el10_2
  • rv RHEL 10.2 6.12.0-211.67.1.el10_2
  • perf RHEL 10.2 6.12.0-211.67.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.67.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.67.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.67.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.67.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.67.1.el10_2

red hat advisories RHSA-2026:85321RHSA-2026:82807RHSA-2026:82806

  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-51.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-51.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-51.1
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-51.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-51.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.73.2
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.73.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.73.2

suse advisories SUSE-SU-2026:23244-1SUSE-SU-2026:23241-1SUSE-SU-2026:23194-1SUSE-SU-2026:23193-1SUSE-SU-2026:3594-1SUSE-SU-2026:3166-1

  • kernel AlmaLinux 9 5.14.0-687.59.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.59.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.59.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.59.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.59.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.59.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.59.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.59.1.el9_8

almalinux advisories ALSA-2026:86033ALSA-2026:85321ALSA-2026:82806ALSA-2026:82807

  • kernel Rocky Linux 9 5.14.0-687.59.1.el9_8
  • kernel Rocky Linux 10 6.12.0-211.67.1.el10_2
  • kernel-rt Rocky Linux 8 4.18.0-553.173.1.rt7.514.el8_10
  • kernel Rocky Linux 8 4.18.0-553.173.1.el8_10

rocky linux advisories RLSA-2026:86033RLSA-2026:85321RLSA-2026:82806RLSA-2026:82807

  • kernel Azure Linux 3.0 6.6.134.1-2

azure linux advisories AZL-84216

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-2026-31678 updated cvss 7.8

kernel: openvswitch: defer tunnel netdev_put to RCU release

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.”
  • Red Hat Enterprise Linux kernel-modules-internal 6.12.0-211.67.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:85321
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.59.1.el9_8, perf 5.14.0-687.59.1.el9_8, rtla 5.14.0-687.59.1.el9_8, python3-perf 5.14.0-687.59.1.el9_8, kernel-devel-matched 5.14.0-687.59.1.el9_8, kernel-64k-devel-matched 5.14.0-687.59.1.el9_8, +7 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:86033
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.67.1.el10_2, perf 6.12.0-211.67.1.el10_2, rtla 6.12.0-211.67.1.el10_2, python3-perf 6.12.0-211.67.1.el10_2, kernel-devel-matched 6.12.0-211.67.1.el10_2, kernel-64k-devel-matched 6.12.0-211.67.1.el10_2, +7 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:85321
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.173.1.el8_10, kernel 4.18.0-553.173.1.el8_10, bpftool 4.18.0-553.173.1.el8_10, kernel-core 4.18.0-553.173.1.el8_10, kernel-tools 4.18.0-553.173.1.el8_10, python3-perf 4.18.0-553.173.1.el8_10, +15 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:82807
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.59.1.el9_8, kernel-64k 5.14.0-687.59.1.el9_8, kernel-core 5.14.0-687.59.1.el9_8, kernel-tools 5.14.0-687.59.1.el9_8, kernel-modules 5.14.0-687.59.1.el9_8, kernel-64k-core 5.14.0-687.59.1.el9_8, +27 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:86033
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.67.1.el10_2, kernel-64k 6.12.0-211.67.1.el10_2, kernel-core 6.12.0-211.67.1.el10_2, kernel-tools 6.12.0-211.67.1.el10_2, kernel-modules 6.12.0-211.67.1.el10_2, kernel-64k-core 6.12.0-211.67.1.el10_2, +28 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:85321
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.59.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.59.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.59.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.59.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.59.1.el9_8
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:86033
show 10 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.67.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:85321
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.173.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.173.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.173.1.el8_10
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:82807
  • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal 6.12.0-211.67.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.67.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:85321
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-kvm 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-core 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-modules 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-debug-kvm 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-debug-core 4.18.0-553.173.1.rt7.514.el8_10, +4 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:82806
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.59.1.el9_8, kernel-rt-64k 5.14.0-687.59.1.el9_8, kernel-rt-core 5.14.0-687.59.1.el9_8, kernel-rt-modules 5.14.0-687.59.1.el9_8, kernel-rt-64k-core 5.14.0-687.59.1.el9_8, kernel-rt-debug-core 5.14.0-687.59.1.el9_8, +14 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:86033
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.67.1.el10_2, kernel-rt-64k 6.12.0-211.67.1.el10_2, kernel-rt-core 6.12.0-211.67.1.el10_2, kernel-rt-modules 6.12.0-211.67.1.el10_2, kernel-rt-64k-core 6.12.0-211.67.1.el10_2, kernel-rt-debug-core 6.12.0-211.67.1.el10_2, +14 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:85321
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.59.1.el9_8, kernel-rt-core 5.14.0-687.59.1.el9_8, kernel-rt-modules 5.14.0-687.59.1.el9_8, kernel-rt-debug-core 5.14.0-687.59.1.el9_8, kernel-rt-modules-core 5.14.0-687.59.1.el9_8, kernel-rt-debug-modules 5.14.0-687.59.1.el9_8, +4 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:86033
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.67.1.el10_2, kernel-rt-core 6.12.0-211.67.1.el10_2, kernel-rt-modules 6.12.0-211.67.1.el10_2, kernel-rt-debug-core 6.12.0-211.67.1.el10_2, kernel-rt-modules-core 6.12.0-211.67.1.el10_2, kernel-rt-debug-modules 6.12.0-211.67.1.el10_2, +4 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:85321
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-core 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-modules 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-debug-core 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-debug-modules 4.18.0-553.173.1.rt7.514.el8_10, kernel-rt-modules-extra 4.18.0-553.173.1.rt7.514.el8_10, +2 more
    fixed: vendor fix “To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2026:82806
  • 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

0.13% chance of exploitation in the next 30 days, higher than 2% 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

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.