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.
Published: 2026-08-15
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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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

Subscriptions

Linux Linux Kernel
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.

Weaknesses

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