{"id":"CVE-2026-72256","title":"netfilter: xt_cluster: reject template conntracks in hash match","summary":"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 t…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 4558bd7b47c7be82dffd837f27be8ea3ecee557d","Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < d5f9d050b0b267227c1f02f11021872c7768a9cc","Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 4cb8b5f586e41c187942291cc0938006077fa79e","Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < fac2fdac3baad9ffd12b3b0bba4374d4b3585d54","Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 13ea4f86cf738c74be2146886ac261988a631e62","Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5","Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa","Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 5feba91006ec92da57acc1cc2e34df623b98541e","Linux 2.6.30"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:53:38.810465Z"},"published":"2026-08-15","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:55:24.042Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72256","references":[{"url":"https://git.kernel.org/stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d"},{"url":"https://git.kernel.org/stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc"},{"url":"https://git.kernel.org/stable/c/4cb8b5f586e41c187942291cc0938006077fa79e"},{"url":"https://git.kernel.org/stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54"},{"url":"https://git.kernel.org/stable/c/13ea4f86cf738c74be2146886ac261988a631e62"},{"url":"https://git.kernel.org/stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5"},{"url":"https://git.kernel.org/stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa"},{"url":"https://git.kernel.org/stable/c/5feba91006ec92da57acc1cc2e34df623b98541e"}],"tags":["cve.org"],"epss":0.00216,"epssPercentile":0.1215,"ingestedAt":"2026-11-06T18:00:12.583Z","slug":"CVE-2026-72256","body":"## Overview\n\nIn 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->_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.\n\n## Affected\n\n- `Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 4558bd7b47c7be82dffd837f27be8ea3ecee557d`\n- `Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < d5f9d050b0b267227c1f02f11021872c7768a9cc`\n- `Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 4cb8b5f586e41c187942291cc0938006077fa79e`\n- `Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < fac2fdac3baad9ffd12b3b0bba4374d4b3585d54`\n- `Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 13ea4f86cf738c74be2146886ac261988a631e62`\n- `Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5`\n- `Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa`\n- `Linux >= 0269ea4937343536ec7e85649932bc8c9686ea78 < 5feba91006ec92da57acc1cc2e34df623b98541e`\n- `Linux 2.6.30`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}