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.

Metrics

No CVSS v4.0

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

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References
Link Providers
https://git.kernel.org/stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5 cve-icon cve-icon
https://git.kernel.org/stable/c/13ea4f86cf738c74be2146886ac261988a631e62 cve-icon cve-icon
https://git.kernel.org/stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d cve-icon cve-icon
https://git.kernel.org/stable/c/4cb8b5f586e41c187942291cc0938006077fa79e cve-icon cve-icon
https://git.kernel.org/stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa cve-icon cve-icon
https://git.kernel.org/stable/c/5feba91006ec92da57acc1cc2e34df623b98541e cve-icon cve-icon
https://git.kernel.org/stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc cve-icon cve-icon
https://git.kernel.org/stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54 cve-icon cve-icon
History

Sat, 15 Aug 2026 06:00:00 +0000

Type Values Removed Values Added
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.
Title netfilter: xt_cluster: reject template conntracks in hash match
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-15T05:54:43.706Z

Reserved: 2026-08-09T03:40:39.915Z

Link: CVE-2026-72256

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-15T06:21:53.310

Modified: 2026-08-15T06:21:53.310

Link: CVE-2026-72256

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.