Uncontrolled Recursion in Linux kernel - CVE-2026-23276

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Main Vulnerability Database Vulnerabilities #VU124175

Uncontrolled Recursion in Linux kernel - CVE-2026-23276

Published: March 20, 2026


Vulnerability identifier: #VU124175
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-23276
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper input validation in tunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) when handling network packets in a specific tunnel and bonding configuration. A remote attacker can send specially crafted network traffic that triggers infinite recursion between bond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), leading to kernel stack overflow and system crash.

The issue specifically occurs when a bond device in broadcast mode has GRE tap interfaces as slaves and those GRE tunnels route back through the bond, causing multicast/broadcast traffic to trigger unbounded recursion. The existing XMIT_RECURSION_LIMIT is insufficient because tunnel recursion consumes more stack per level due to route lookups and full IP output processing.


Affected software

Linux kernel
Debian Linux
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Development Tools Module
Basesystem Module
SUSE Real Time Module
Ubuntu
openEuler
kgraft-patch-4_12_14-122_310-default
kernel-livepatch-6_4_0-150700_7_54-rt
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo
kernel-livepatch-6_4_0-150700_7_67-rt
kernel-livepatch-SLE15-SP7-RT_Update_18-debugsource
kernel-livepatch-6_4_0-150700_7_67-rt-debuginfo
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_15-debugsource
kernel-livepatch-6_4_0-150700_53_55-default
kernel-livepatch-6_4_0-150700_53_73-default-debuginfo
kernel-livepatch-6_4_0-150700_53_73-default
kernel-livepatch-SLE15-SP7_Update_19-debugsource
kernel-default-devel
kernel-default-debugsource
dlm-kmp-default
cluster-md-kmp-default
ocfs2-kmp-default-debuginfo
kernel-default-base-debuginfo
ocfs2-kmp-default
dlm-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
kernel-default-base
kernel-syms
gfs2-kmp-default
gfs2-kmp-default-debuginfo
kernel-default-debuginfo
kernel-default
kernel-source
kernel-devel
kernel-macros
kernel-default-man
kernel-default-devel-debuginfo
kernel-default-kgraft
kernel-default-kgraft-devel
cluster-md-kmp-rt
kernel-rt
kernel-source-rt
kernel-devel-rt
gfs2-kmp-rt-debuginfo
dlm-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-rt-devel
dlm-kmp-rt-debuginfo
kernel-rt-devel-debuginfo
kernel-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-rt-debugsource
gfs2-kmp-rt
kernel-syms-rt
ocfs2-kmp-rt
kernel-64kb-devel
kernel-64kb-devel-debuginfo
kernel-64kb
kernel-64kb-debuginfo
kernel-64kb-debugsource
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-docs
kernel-obs-build
kernel-obs-build-debugsource
kernel-default-livepatch-devel
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-azure
kernel-azure-debugsource
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-devel
kernel-default-extra-debuginfo
kernel-default-extra
kernel-default-livepatch
bpftool
kernel
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-headers
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo
kernel-extra-modules
linux (Ubuntu package)
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-aws (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux (Debian package)

How to mitigate CVE-2026-23276

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_310-default - update to 1-8.3.1
kernel-livepatch-6_4_0-150700_7_54-rt - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_67-rt - update to 1-150700.1.5.1
kernel-livepatch-SLE15-SP7-RT_Update_18-debugsource - update to 1-150700.1.5.1
kernel-livepatch-6_4_0-150700_7_67-rt-debuginfo - update to 1-150700.1.5.1
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_15-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_55-default - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_73-default-debuginfo - update to 1-150700.15.3.4
kernel-livepatch-6_4_0-150700_53_73-default - update to 1-150700.15.3.4
kernel-livepatch-SLE15-SP7_Update_19-debugsource - update to 1-150700.15.3.4
kernel-default-devel - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-debugsource - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
dlm-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
cluster-md-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
ocfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-base-debuginfo - update to 4.12.14-122.310.1
ocfs2-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
dlm-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
cluster-md-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-base - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1.150700.17.33.1, 6.4.0-150700.53.73.2.150700.17.41.4
kernel-syms - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.1
gfs2-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
gfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-source - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.1
kernel-devel - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.1
kernel-macros - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.1
kernel-default-man - update to 4.12.14-122.310.1
kernel-default-devel-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-kgraft - update to 4.12.14-122.310.1
kernel-default-kgraft-devel - update to 4.12.14-122.310.1
cluster-md-kmp-rt - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-rt - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-source-rt - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-devel-rt - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
gfs2-kmp-rt-debuginfo - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
dlm-kmp-rt - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
ocfs2-kmp-rt-debuginfo - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-rt-devel - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
dlm-kmp-rt-debuginfo - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-rt-devel-debuginfo - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-rt-debuginfo - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
cluster-md-kmp-rt-debuginfo - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-rt-debugsource - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
gfs2-kmp-rt - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-syms-rt - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
ocfs2-kmp-rt - addressed in versions 6.4.0-150700.7.54.1, 6.4.0-150700.7.67.1
kernel-64kb-devel - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-64kb-devel-debuginfo - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-64kb - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-64kb-debuginfo - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-64kb-debugsource - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-zfcpdump-debugsource - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-zfcpdump-debuginfo - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-zfcpdump - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-docs - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.1
kernel-obs-build - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-obs-build-debugsource - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-livepatch-devel - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
reiserfs-kmp-default-debuginfo - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
reiserfs-kmp-default - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-azure - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-azure-debugsource - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-azure-debuginfo - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-azure-devel-debuginfo - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-azure-devel - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-extra-debuginfo - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-extra - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
kernel-default-livepatch - addressed in versions 6.4.0-150700.53.55.1, 6.4.0-150700.53.73.2
bpftool - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debugsource - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-headers - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-source - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-devel - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-extra-modules - update to 6.6.0-145.0.2.143
linux (Ubuntu package) - addressed in versions 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-aws (Ubuntu package) - update to 6.8.0-1061.64+1
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1061.65, 6.8.0-2050.52
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1
linux (Debian package) - update to 6.12.85-1

External References

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