Use-after-free in Linux kernel - CVE-2026-98862
Published: October 22, 2026
Vulnerability details
The vulnerability allows a local privileged user to potentially cause a denial of service through a kernel use-after-free.
The vulnerability exists due to use-after-free in the Linux kernel audit subsystem's kill_rules() function when pruning an audit tree containing mixed AUDIT_DIR and AUDIT_EXE rules. A local privileged user can install a rule using AUDIT_ADD_RULE with CAP_AUDIT_CONTROL and remove the watched directory while another task evaluates the rule, causing audit_mark_compare() to access an executable mark already freed by fsnotify and potentially trigger a kernel crash.
Affected software
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-2026-98862
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
- https://git.kernel.org/stable/c/304960900991157e6883bdf0b39782b690545ee8
- https://git.kernel.org/stable/c/88633025f20ba9c32ccdb3efc86eafdf98cb825c
- https://git.kernel.org/stable/c/9aee3caeff4dd4126d84f67607b95cec8719b867
- https://git.kernel.org/stable/c/aa650d87a498844060eecb1d336f4d46f4d1b0b3
- https://git.kernel.org/stable/c/f2cc5462b78559c7628a9f8ac9a9592e7783183a
Related Security Bulletins
- Use-after-free in Linux kernel kernel/audit_tree.c: kill_rules(); audit_mark_compare()
- Ubuntu update for linux, linux-aws, linux-gcp and more
- Ubuntu update for linux-azure
- Ubuntu update for linux-aws-7.0, linux-azure-fde, linux-azure-fde-7.0 and more
- Ubuntu update for linux-aws-fips, linux-gcp-fips, linux-gkeop and more
- Ubuntu update for linux-azure-6.8, linux-azure-fde-6.8
- Ubuntu update for linux-oracle-6.8, linux-raspi, linux-raspi-realtime
- Ubuntu update for linux-aws-6.8, linux-gcp-6.8, linux-ibm-6.8 and more
- Ubuntu update for linux, linux-aws, linux-azure and more
- Ubuntu update for linux-raspi