{"id":"CVE-2026-72256","state":"PUBLISHED","title":"netfilter: xt_cluster: reject template conntracks in hash match","description":"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->_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.","publishedAt":"2026-08-15T05:54:43.706Z","updatedAt":"2026-08-17T05:11:14.683Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"4558bd7b47c7be82dffd837f27be8ea3ecee557d","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"d5f9d050b0b267227c1f02f11021872c7768a9cc","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"4cb8b5f586e41c187942291cc0938006077fa79e","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"fac2fdac3baad9ffd12b3b0bba4374d4b3585d54","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"13ea4f86cf738c74be2146886ac261988a631e62","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"5feba91006ec92da57acc1cc2e34df623b98541e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/xt_cluster.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.30","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.30","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/xt_cluster.c"]}],"references":["https://git.kernel.org/stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d","https://git.kernel.org/stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc","https://git.kernel.org/stable/c/4cb8b5f586e41c187942291cc0938006077fa79e","https://git.kernel.org/stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54","https://git.kernel.org/stable/c/13ea4f86cf738c74be2146886ac261988a631e62","https://git.kernel.org/stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5","https://git.kernel.org/stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa","https://git.kernel.org/stable/c/5feba91006ec92da57acc1cc2e34df623b98541e"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72256.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72256","state":"PUBLISHED","datePublished":"2026-08-15T05:54:43.706Z","dateUpdated":"2026-08-17T05:11:14.683Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.915Z"},"containers":{"cna":{"title":"netfilter: xt_cluster: reject template conntracks in hash match","descriptions":[{"lang":"en","value":"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->_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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"4558bd7b47c7be82dffd837f27be8ea3ecee557d","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"d5f9d050b0b267227c1f02f11021872c7768a9cc","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"4cb8b5f586e41c187942291cc0938006077fa79e","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"fac2fdac3baad9ffd12b3b0bba4374d4b3585d54","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"13ea4f86cf738c74be2146886ac261988a631e62","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa","versionType":"git"},{"version":"0269ea4937343536ec7e85649932bc8c9686ea78","status":"affected","lessThan":"5feba91006ec92da57acc1cc2e34df623b98541e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/xt_cluster.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.30","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.30","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/xt_cluster.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:11:14.683Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}