Use-after-free in Linux kernel - CVE-2026-63922

CSH
CYBERSECURITY HELP
Sign In REGISTER
 
Main Vulnerability Database Vulnerabilities #VU138727

Use-after-free in Linux kernel - CVE-2026-63922

Published: July 20, 2026


Vulnerability identifier: #VU138727
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-2026-63922
CWE-ID: CWE-416
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 a use-after-free risk from stale pointer reuse in ip6_parse_tlv() in net/ipv6/exthdrs.c when parsing IPv6 TLVs containing the HAO option. A remote attacker can send a specially crafted IPv6 packet to cause a denial of service.

The issue occurs when handling a cloned skb where header expansion moves the skb head and invalidates the cached network header pointer.


Affected software

Linux kernel
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME
SUSE Linux Enterprise Server 11
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support
Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support
Ubuntu
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
kernel (Red Hat package)
kernel-xen-base
kernel-ec2-debuginfo
kernel-trace-devel-debuginfo
kernel-source
kernel-xen-debuginfo
kernel-default-devel-debuginfo
kernel-default-devel
kernel-ec2-devel
kernel-trace-debugsource
kernel-xen-devel
kernel-default-base
kernel-trace-devel
kernel-default-debuginfo
kernel-xen-devel-debuginfo
kernel-ec2-base
kernel-trace-debuginfo
kernel-trace-base
kernel-ec2-devel-debuginfo
kernel-xen-debugsource
kernel-ec2-debugsource
kernel-default-debugsource
kernel-syms
kernel-ec2
kernel-trace
kernel-default
kernel-xen
kernel-docs
linux-aws (Ubuntu package)
linux (Ubuntu package)
linux-fips (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-63922

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel (Red Hat package) - addressed in versions 2.6.32-754.65.1.el6, 4.18.0-305.214.1.el8_4, 4.18.0-372.223.1.el8_6, 4.18.0-477.175.1.el8_8, 5.14.0-427.154.1.el9_4, 5.14.0-687.55.1.el9_8, 6.12.0-55.111.1.el10_0
kernel-xen-base - update to 3.0.101-108.216.1
kernel-ec2-debuginfo - update to 3.0.101-108.216.1
kernel-trace-devel-debuginfo - update to 3.0.101-108.216.1
kernel-source - update to 3.0.101-108.216.1
kernel-xen-debuginfo - update to 3.0.101-108.216.1
kernel-default-devel-debuginfo - update to 3.0.101-108.216.1
kernel-default-devel - update to 3.0.101-108.216.1
kernel-ec2-devel - update to 3.0.101-108.216.1
kernel-trace-debugsource - update to 3.0.101-108.216.1
kernel-xen-devel - update to 3.0.101-108.216.1
kernel-default-base - update to 3.0.101-108.216.1
kernel-trace-devel - update to 3.0.101-108.216.1
kernel-default-debuginfo - update to 3.0.101-108.216.1
kernel-xen-devel-debuginfo - update to 3.0.101-108.216.1
kernel-ec2-base - update to 3.0.101-108.216.1
kernel-trace-debuginfo - update to 3.0.101-108.216.1
kernel-trace-base - update to 3.0.101-108.216.1
kernel-ec2-devel-debuginfo - update to 3.0.101-108.216.1
kernel-xen-debugsource - update to 3.0.101-108.216.1
kernel-ec2-debugsource - update to 3.0.101-108.216.1
kernel-default-debugsource - update to 3.0.101-108.216.1
kernel-syms - update to 3.0.101-108.216.1
kernel-ec2 - update to 3.0.101-108.216.1
kernel-trace - update to 3.0.101-108.216.1
kernel-default - update to 3.0.101-108.216.1
kernel-xen - update to 3.0.101-108.216.1
kernel-docs - update to 3.0.101-108.216.1
linux-aws (Ubuntu package) - addressed in versions 5.15.0-194.204~20.04.1, 5.15.0-194.204, 5.15.0-1079.83, 5.15.0-1099.107, 5.15.0-1108.110, 5.15.0-1108.113, 5.15.0-1110.114, 5.15.0-1111.117, 5.15.0-1112.118, 5.15.0-1113.119, 5.15.0-1115.124, 5.15.0-1116.123, 5.15.0-1116.123+fips1, 5.15.0-1116.126+fips1, 5.15.0-1117.127, 5.15.0-1121.130, 5.15.0-1122.131, 5.15.0-1122.131+fips1, 5.15.0.194.159, 5.15.0.1079.82, 5.15.0.1099.98, 5.15.0.1108.104, 5.15.0.1108.112, 5.15.0.1110.107, 5.15.0.1111.110, 5.15.0.1112.111, 5.15.0.1113.109, 5.15.0.1115.119, 5.15.0.1116.106, 5.15.0.1116.112, 5.15.0.1116.119, 5.15.0.1117.114, 5.15.0.1122.106, 5.15.0.1122.120, 6.8.0-1065.68~22.04.1, 6.8.0-1065.68, 7.0.0-1009.9, 7.0.0-1015.15
linux (Ubuntu package) - addressed in versions 5.15.0-194.204, 5.15.0-1111.112, 5.15.0.194.171, 5.15.0.1111.111, 6.8.0-142.142+fips1, 6.8.0-142.142.1~22.04.1, 6.8.0-142.142.1, 6.8.0-1050.54, 6.8.0-1062.65~22.04.1, 6.8.0-1064.72+fips1, 6.8.0-1065.66, 6.8.0-1065.69, 6.8.0-1066.73~22.04.1, 6.8.0-1066.73, 6.8.0-1068.76~22.04.1, 6.8.0-1068.76, 6.8.0-1068.76+fips1, 6.8.0-1069.77~22.04.1, 6.8.0-1069.77, 6.8.0-2054.56, 6.8.1-1060.61~22.04.1, 6.8.1-1060.61
linux-fips (Ubuntu package) - addressed in versions 5.15.0-194.204+fips1, 5.15.0.194.113
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1057.57, 5.15.0-1068.70, 5.15.0.1057.59, 5.15.0.1068.68, 6.8.0-1035.38
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1068.70~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1110.114~20.04.1
linux-aws-5.15 (Ubuntu package) - addressed in versions 5.15.0-1111.117~20.04.1, 5.15.0-1116.123~20.04.1, 5.15.0-1121.130~20.04.1, 5.15.0-1122.131~20.04.1
linux-oracle-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.120~20.04.1, 5.15.0.1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1118.128~20.04.1, 5.15.0.1118.128~20.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1063.66~22.04.1, 6.8.0-1063.66, 6.8.0-1063.66.1, 7.0.0-1016.16~24.04.1, 7.0.0-1016.16
linux-aws-fips (Ubuntu package) - update to 6.8.0-1065.68+fips1
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

External References

Related Security Bulletins