Always-Incorrect Control Flow Implementation in Linux kernel - CVE-2026-72256
Published: August 16, 2026
Vulnerability identifier: #VU143183
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-2026-72256
CWE-ID: CWE-670
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper handling of template conntrack state in xt_cluster_mt() in the netfilter xt_cluster matcher when processing packets associated with a template conntrack. A local user can trigger packet processing that reaches xt_cluster_hash() with incomplete conntrack state to cause a denial of service.
The issue occurs when the raw table CT target attaches a template conntrack to skb->_nfct before normal conntrack processing.
Affected software
Linux kernel
How to mitigate CVE-2026-72256
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5
- https://git.kernel.org/stable/c/13ea4f86cf738c74be2146886ac261988a631e62
- https://git.kernel.org/stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d
- https://git.kernel.org/stable/c/4cb8b5f586e41c187942291cc0938006077fa79e
- https://git.kernel.org/stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa
- https://git.kernel.org/stable/c/5feba91006ec92da57acc1cc2e34df623b98541e
- https://git.kernel.org/stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc
- https://git.kernel.org/stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54