Improper input validation in Linux kernel - CVE-2026-98852

 

Improper input validation in Linux kernel - CVE-2026-98852

Published: October 22, 2026


Vulnerability identifier: #VU157221
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-98852
CWE-ID: CWE-20
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to disrupt network communication by triggering the dropping of tunneled IPv6 packets.

The vulnerability exists due to improper validation of IPv6 extension headers in the Linux kernel's segmentation and checksum offload handling in net/core/dev.c when processing tunneled packets. A local user can generate affected tunneled traffic that reaches an incompatible software checksum fallback path, triggering kernel warnings and packet drops that disrupt network communication.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-realtime (Ubuntu package)
linux-lowlatency-hwe-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure-6.8 (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-gke (Ubuntu package)
linux-vmware (Ubuntu package)
linux-ibm-6.8 (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime-6.8 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-azure-fde-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-aws-7.0 (Ubuntu package)

How to mitigate CVE-2026-98852

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 6.8.0-149.149, 7.0.0-43.43
linux-lowlatency (Ubuntu package) - update to 6.8.0-149.149.1
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1068.72, 7.0.0-1023.23
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1073.82, 7.0.0-1020.21
linux-gcp (Ubuntu package) - addressed in versions 6.8.0-1073.81, 7.0.0-1017.19
linux-aws (Ubuntu package) - addressed in versions 6.8.0-1069.74, 7.0.0-1017.18
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1069.70, 7.0.0-1018.18
linux-oracle (Ubuntu package) - addressed in versions 6.8.0-1067.71, 7.0.0-1016.18
linux-nvidia (Ubuntu package) - update to 6.8.0-1067.70
linux-realtime (Ubuntu package) - addressed in versions 6.8.1-1064.65, 7.0.0-43.43.1
linux-lowlatency-hwe-6.8 (Ubuntu package) - update to 6.8.0-149.149.1~22.04.1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1071.78~22.04.1
linux-azure-6.8 (Ubuntu package) - update to 6.8.0-1073.82~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1067.71~22.04.1
linux-aws-6.8 (Ubuntu package) - update to 6.8.0-1069.74~22.04.1
linux-gkeop (Ubuntu package) - update to 6.8.0-1053.57
linux-gke (Ubuntu package) - addressed in versions 6.8.0-1068.77, 7.0.0-1010.11
linux-vmware (Ubuntu package) - update to 6.8.0-1010.10
linux-ibm-6.8 (Ubuntu package) - update to 6.8.0-1069.70~22.04.1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1073.81~22.04.1
linux-aws-fips (Ubuntu package) - update to 6.8.0-1069.74+fips1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1073.81+fips1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1073.82+fips1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2056.58
linux-realtime-6.8 (Ubuntu package) - update to 6.8.1-1064.65~22.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1016.18~24.04.1
linux-azure-fde-7.0 (Ubuntu package) - update to 7.0.0-1019.19~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1017.19~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1018.18
linux-azure-fde (Ubuntu package) - update to 7.0.0-1019.19
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1017.18~24.04.1

External References

Related Security Bulletins