CVE-2026-97985: af_unix: Update last skb marker in manage_oob().

Published Sep 25, 2026
·
Updated

afunix: Update last skb marker in manageoob().

Affected Software

200 affected componentsFixes available
Linux Linux kernel
Microsoft azl3 kernel 6.6.157.1-1<6.6.159.1-1
6.6.159.1-1
debian/linux<=6.1.176-1, <=6.1.190-1, <=6.12.107-1
6.12.115-27.2.12-17.2.15-1
debian/linux-6.12
6.12.113-1~deb12u1
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.15*
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.15*
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.15*
ubuntu/linux-gcp-5.8*
ubuntu/linux-gke*
ubuntu/linux-gke-5.15*
ubuntu/linux-gkeop*
ubuntu/linux-gkeop-5.15*
ubuntu/linux-hwe-5.11*
ubuntu/linux-hwe-5.13*
ubuntu/linux-hwe-5.15*
ubuntu/linux-hwe-5.8*
ubuntu/linux-ibm-5.15*
ubuntu/linux-intel-5.13*
ubuntu/linux-intel-iotg-5.15*
ubuntu/linux-lowlatency-hwe-5.15*
ubuntu/linux-nvidia-tegra-5.15*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.15*
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.15*
ubuntu/linux-riscv-5.8*
ubuntu/linux*
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws*
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8*
ubuntu/linux-azure*
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8*
ubuntu/linux-gke*
ubuntu/linux-gkeop*
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-ibm*
ubuntu/linux-ibm-6.8*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-intel-iotg*
ubuntu/linux-kvm*
ubuntu/linux-lowlatency*
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8*
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8*
ubuntu/linux-nvidia-tegra*
ubuntu/linux-nvidia-tegra-igx*
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle*
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8*
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8*
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-xilinx-zynqmp*
ubuntu/linux-bluefield*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-realtime*
ubuntu/linux-realtime-6.8*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-aws-7.0*
ubuntu/linux-azure*
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-7.0*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-fde-6.17*
ubuntu/linux-azure-fde-7.0*
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp*
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-7.0*
ubuntu/linux-gke*
ubuntu/linux-gkeop*
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0<7.0.0-42.42~24.04.1
7.0.0-42.42~24.04.1
ubuntu/linux-ibm*
ubuntu/linux-lowlatency*
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17*
ubuntu/linux-nvidia-7.0*
ubuntu/linux-nvidia-lowlatency*
ubuntu/linux-nvidia-tegra*
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17*
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle*
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-oracle-7.0*
ubuntu/linux-raspi*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17*
ubuntu/linux-riscv-7.0<7.0.0-42.42.1~24.04.1
7.0.0-42.42.1~24.04.1
ubuntu/linux-xilinx*
ubuntu/linux-bluefield*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<7.0.0-42.42
7.0.0-42.42
ubuntu/linux-aws<7.0.0-1016.17
7.0.0-1016.17
ubuntu/linux-azure*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp<7.0.0-1016.18
7.0.0-1016.18
ubuntu/linux-gke*
ubuntu/linux-ibm<7.0.0-1017.17
7.0.0-1017.17
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-bos*
ubuntu/linux-oem-7.0<7.0.0-1017.17
7.0.0-1017.17
ubuntu/linux-oracle<7.0.0-1015.16
7.0.0-1015.16
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv<7.0.0-42.42.1
7.0.0-42.42.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.6.159.1-1
  2. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1
  3. Upgrade

    Upgrade debian/linux-6.12 to a version that resolves this vulnerability.

    Fixed in 6.12.113-1~deb12u1
  4. Upgrade

    Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-42.42~24.04.1
  5. Upgrade

    Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-42.42.1~24.04.1
  6. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 7.0.0-42.42
  7. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 7.0.0-1016.17
  8. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 7.0.0-1016.18
  9. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17
  10. Upgrade

    Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17
  11. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 7.0.0-1015.16
  12. Upgrade

    Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.

    Fixed in 7.0.0-42.42.1

Event History

Sep 25, 2026
CVE Published
via MITRE·10:23 AM
Data Sourced
via MITRE·10:23 AM
Description
Data Sourced
via OSV·11:17 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·11:17 AM
Description
Sep 28, 2026
Data Sourced
via Microsoft·08:36 AM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What conditions are needed to trigger the CPU hog?

The issue requires an AF_UNIX SOCK_STREAM socket handling out-of-band data and a blocking recv(MSG_PEEK) call after OOB skb entries have been skipped or consumed. The described cases include a zero-length MSG_PEEK receive and sequences involving MSG_OOB receives.

2

What is the observable impact?

The affected thread can busy-wait for a new skb and hog CPU. This occurs because the data-wait path returns immediately while no data has been copied.

3

How can I tell whether a system is encountering this issue?

Look for CPU consumption by a thread blocked in AF_UNIX stream receive handling, particularly where recv(MSG_PEEK) follows MSG_OOB activity. The reproductions use socketpair(AF_UNIX, SOCK_STREAM, 0, sk) and the specific OOB/peek receive sequences described in the advisory.

Contact

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