CVE-2026-72256

medium

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_cluster: reject template conntracks in hash match xt_cluster_mt() treats any non-NULL nf_ct_get() result as a fully initialized conntrack and passes it to xt_cluster_hash(). This causes a state confusion bug when the raw table CT target attaches a template conntrack to skb->_nfct before normal conntrack processing. Templates carry IPS_TEMPLATE status but do not have a valid tuple for hashing yet, so xt_cluster_hash() can hit its WARN_ON() path on the zeroed l3num field. Reject template conntracks before hashing them. This matches existing netfilter handling for template objects and avoids hashing incomplete conntrack state.

References

https://git.kernel.org/stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54

https://git.kernel.org/stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc

https://git.kernel.org/stable/c/5feba91006ec92da57acc1cc2e34df623b98541e

https://git.kernel.org/stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa

https://git.kernel.org/stable/c/4cb8b5f586e41c187942291cc0938006077fa79e

https://git.kernel.org/stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d

https://git.kernel.org/stable/c/13ea4f86cf738c74be2146886ac261988a631e62

https://git.kernel.org/stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5

Details

Source: Mitre, NVD

Published: 2026-08-15

Updated: 2026-08-17

Risk Information

CVSS v2

Base Score: 4.9

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 5.5

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

EPSS

EPSS: 0.0022