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Fencer Vulns
high 7.5

CVE-2026-68299 json

vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets

published 2026-08-10 2 mo ago modified 2026-10-19 20 d ago also EUVD-2026-55400

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

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

vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets

vmxnet3_get_hdr_len() assumes gdesc->rcd.v4/v6/tcp always describe the outer header, but for a Geneve-encapsulated packet the device can set them based on the inner header instead, signalled by the VMXNET3_RCD_HDR_INNER_SHIFT bit in the completion descriptor. Since the function never skips the outer encapsulation, this mismatch triggers:

- BUG_ON(hdr.ipv4->protocol != IPPROTO_TCP), because the outer protocol is UDP (Geneve), not TCP. - BUG_ON(hdr.eth->h_proto != ...), when the tunnel's outer and inner IP versions differ (e.g. outer IPv6/inner IPv4 or vice versa).

Check VMXNET3_RCD_HDR_INNER_SHIFT up front and bail out, since the function cannot locate the inner header it would need to parse. Also convert the remaining BUG_ON()s in this function to return 0 defensively.

Patch / fix

  • Linux Linux 5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2
  • linux Debian 12 6.1.187-1
  • linux Debian 13 6.12.101-1
  • linux Debian 14 7.1.6-1
  • linux-6.12 Debian 12 6.12.101-1~deb12u1

debian advisories DEBIAN-CVE-2026-68299

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-38.38
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-68299

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 8 4.18.0-553.170.1.el8_10
  • perf RHEL 8 4.18.0-553.170.1.el8_10
  • bpftool RHEL 8 4.18.0-553.170.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.170.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.170.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.170.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.170.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.170.1.el8_10

red hat advisories RHSA-2026:74133RHSA-2026:74132RHSA-2026:72624

  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.81.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.81.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
  • kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1.150700.17.45.1

suse advisories SUSE-SU-2026:4254-1SUSE-SU-2026:23887-1SUSE-SU-2026:23902-1SUSE-SU-2026:23897-1SUSE-SU-2026:23881-1SUSE-SU-2026:4282-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1

  • kernel AlmaLinux 9 5.14.0-687.60.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.60.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.60.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.60.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.60.1.el9_8

almalinux advisories ALSA-2026:87805ALSA-2026:74132ALSA-2026:74133ALSA-2026:72624

  • kernel Rocky Linux 9 5.14.0-687.60.1.el9_8
  • kernel-rt Rocky Linux 8 4.18.0-553.170.1.rt7.511.el8_10
  • kernel Rocky Linux 8 4.18.0-553.170.1.el8_10
  • kernel Rocky Linux 10 6.12.0-211.61.1.el10_2

rocky linux advisories RLSA-2026:87805RLSA-2026:74132RLSA-2026:74133RLSA-2026:72624

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-2026-68299 updated cvss 5.5

kernel: vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • 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: no fix available
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.60.1.el9_8, perf 5.14.0-687.60.1.el9_8, rtla 5.14.0-687.60.1.el9_8, python3-perf 5.14.0-687.60.1.el9_8, kernel-devel-matched 5.14.0-687.60.1.el9_8, kernel-64k-devel-matched 5.14.0-687.60.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:87805
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.61.1.el10_2, perf 6.12.0-211.61.1.el10_2, rtla 6.12.0-211.61.1.el10_2, python3-perf 6.12.0-211.61.1.el10_2, kernel-devel-matched 6.12.0-211.61.1.el10_2, kernel-64k-devel-matched 6.12.0-211.61.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:72624
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.170.1.el8_10, kernel 4.18.0-553.170.1.el8_10, bpftool 4.18.0-553.170.1.el8_10, kernel-core 4.18.0-553.170.1.el8_10, kernel-tools 4.18.0-553.170.1.el8_10, python3-perf 4.18.0-553.170.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:74133
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.60.1.el9_8, kernel-64k 5.14.0-687.60.1.el9_8, kernel-core 5.14.0-687.60.1.el9_8, kernel-tools 5.14.0-687.60.1.el9_8, kernel-modules 5.14.0-687.60.1.el9_8, kernel-64k-core 5.14.0-687.60.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:87805
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.61.1.el10_2, kernel-64k 6.12.0-211.61.1.el10_2, kernel-core 6.12.0-211.61.1.el10_2, kernel-tools 6.12.0-211.61.1.el10_2, kernel-modules 6.12.0-211.61.1.el10_2, kernel-64k-core 6.12.0-211.61.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:72624
show 9 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.60.1.el9_8
    fixed: vendor fix RHSA-2026:87805
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.61.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.61.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.61.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.61.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.61.1.el10_2
    fixed: vendor fix RHSA-2026:72624
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.170.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.170.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.170.1.el8_10
    fixed: vendor fix RHSA-2026:74133
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-kvm 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-core 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-modules 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-debug-kvm 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-debug-core 4.18.0-553.170.1.rt7.511.el8_10, +4 more
    fixed: vendor fix RHSA-2026:74132
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.60.1.el9_8, kernel-rt-64k 5.14.0-687.60.1.el9_8, kernel-rt-core 5.14.0-687.60.1.el9_8, kernel-rt-modules 5.14.0-687.60.1.el9_8, kernel-rt-64k-core 5.14.0-687.60.1.el9_8, kernel-rt-debug-core 5.14.0-687.60.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:87805
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.61.1.el10_2, kernel-rt-64k 6.12.0-211.61.1.el10_2, kernel-rt-core 6.12.0-211.61.1.el10_2, kernel-rt-modules 6.12.0-211.61.1.el10_2, kernel-rt-64k-core 6.12.0-211.61.1.el10_2, kernel-rt-debug-core 6.12.0-211.61.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:72624
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.60.1.el9_8, kernel-rt-core 5.14.0-687.60.1.el9_8, kernel-rt-modules 5.14.0-687.60.1.el9_8, kernel-rt-debug-core 5.14.0-687.60.1.el9_8, kernel-rt-modules-core 5.14.0-687.60.1.el9_8, kernel-rt-debug-modules 5.14.0-687.60.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:87805
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.61.1.el10_2, kernel-rt-core 6.12.0-211.61.1.el10_2, kernel-rt-modules 6.12.0-211.61.1.el10_2, kernel-rt-debug-core 6.12.0-211.61.1.el10_2, kernel-rt-modules-core 6.12.0-211.61.1.el10_2, kernel-rt-debug-modules 6.12.0-211.61.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:72624
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-core 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-modules 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-debug-core 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-debug-modules 4.18.0-553.170.1.rt7.511.el8_10, kernel-rt-modules-extra 4.18.0-553.170.1.rt7.511.el8_10, +2 more
    fixed: vendor fix RHSA-2026:74132

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
yes
Technical impact
partial
Assessed
23 d ago

Exploit prediction

0.50% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-20 Improper Input Validation
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.