{"id":"CVE-2026-72256","summary":"netfilter: xt_cluster: reject template conntracks in hash match","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_cluster: reject template conntracks in hash match\n\nxt_cluster_mt() treats any non-NULL nf_ct_get() result as a fully\ninitialized conntrack and passes it to xt_cluster_hash().\n\nThis causes a state confusion bug when the raw table CT target attaches\na template conntrack to skb-\u003e_nfct before normal conntrack processing.\nTemplates carry IPS_TEMPLATE status but do not have a valid tuple for\nhashing yet, so xt_cluster_hash() can hit its WARN_ON() path on the\nzeroed l3num field.\n\nReject template conntracks before hashing them. This matches existing\nnetfilter handling for template objects and avoids hashing incomplete\nconntrack state.","modified":"2026-08-18T03:31:25.362364235Z","published":"2026-08-15T05:54:43.706Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72256.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/13ea4f86cf738c74be2146886ac261988a631e62"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4cb8b5f586e41c187942291cc0938006077fa79e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5feba91006ec92da57acc1cc2e34df623b98541e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72256.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72256"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0269ea4937343536ec7e85649932bc8c9686ea78"},{"fixed":"4558bd7b47c7be82dffd837f27be8ea3ecee557d"},{"fixed":"d5f9d050b0b267227c1f02f11021872c7768a9cc"},{"fixed":"4cb8b5f586e41c187942291cc0938006077fa79e"},{"fixed":"fac2fdac3baad9ffd12b3b0bba4374d4b3585d54"},{"fixed":"13ea4f86cf738c74be2146886ac261988a631e62"},{"fixed":"07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5"},{"fixed":"5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa"},{"fixed":"5feba91006ec92da57acc1cc2e34df623b98541e"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72256.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.30"},{"fixed":"5.10.261"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72256.json"}}],"schema_version":"1.9.0"}