Reachable assertion in Linux kernel - CVE-2026-98622

Vulnerability identifier: #VU156932

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98622

CWE-ID: CWE-617

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service by triggering a kernel panic.

The vulnerability exists due to a reachable warning assertion in tcf_ct_flow_table_add() in net/sched/act_ct.c when flow_offload_alloc() returns NULL during packet processing through a tc action ct commit classifier. A local user can race a conntrack flush against traffic handled by the classifier to trigger a warning on an expected allocation failure and cause a kernel panic.

The kernel panic requires panic_on_warn=1.

Linux kernel
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - update to 7.0.0-42.42
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/00734f3684fcec42c319bedfe68a5d357c720b53
• https://git.kernel.org/stable/c/424ba52c0058deeb940d02cba52eb0aeb288db33
• https://git.kernel.org/stable/c/47abe7a5c4eb53269aca3506446f851572a059a3
• https://git.kernel.org/stable/c/650787233c2fd6e515a7c5f371019a9fa080ccd2
• https://git.kernel.org/stable/c/af475f599270e59313552e6c6f3af8507da672b8
• https://git.kernel.org/stable/c/d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a
• https://git.kernel.org/stable/c/d805560ad69cb266d669341ca01e26bffb0d2c67
• https://git.kernel.org/stable/c/e8fcf3f08834e939b797311742ee72b1e2a08096

• Reachable assertion in Linux kernel sched
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more