CVE-2026-72256
netfilter: xt_cluster: reject template conntracks in hash match
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
2.6.30
References 8
git.kernel.org
- stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d
- stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc
- stable/c/4cb8b5f586e41c187942291cc0938006077fa79e
- stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54
- stable/c/13ea4f86cf738c74be2146886ac261988a631e62
- stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5
- stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa
- stable/c/5feba91006ec92da57acc1cc2e34df623b98541e