{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72435", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.929Z", "datePublished": "2026-08-15T05:56:49.402Z", "dateUpdated": "2026-08-17T05:44:10.925Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:44:10.925Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer()\n\nSashiko pointed out that kfree_rcu() was called before\nrcu_assign_pointer() in handling the comment extension.\nFix the order so that rcu_assign_pointer() called first." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only through nfnetlink IPSET commands (ADD/DEL/LIST/SAVE) on NETLINK_GENERIC; nfnetlink_rcv() requires CAP_NET_ADMIN and no remote packet path feeds comment free/replace, so kernel CNA guidance treats netfilter/ipset netlink as Local.\nAC:L - LIST/SAVE dump runs asynchronously without holding the nfnl mutex while mtype_list holds rcu_read_lock and calls ip_set_put_comment; an attacker with CAP_NET_ADMIN can concurrently issue ADD/--exist comment replacement, DEL/flush, or timeout GC to hit the kfree_rcu-before-NULL ordering reliably.\nPR:L - nfnetlink_rcv() gates every ipset command on netlink_net_capable(skb, CAP_NET_ADMIN), which resolves to ns_capable(sock_net()->user_ns, CAP_NET_ADMIN); unprivileged users obtain this inside a user/network namespace via unshare -Urn and fully control per-netns ipset configuration.\nUI:N - Exploitation is fully attacker-driven through netlink: create a comment-enabled set, start LIST/SAVE dump, and concurrently add/delete/flush elements or let timeout GC run; no victim click, mount, or other deliberate action is required beyond ordinary local control.\nS:U - The RCU use-after-free corrupts kernel heap memory and can yield host privilege escalation or crash, but impact stays within the same kernel security authority and does not cross VM/host, container/host, or IOMMU boundaries.\nC:H - Calling kfree_rcu() before rcu_assign_pointer(NULL) lets dump readers under rcu_read_lock still rcu_dereference(comment->c) and nla_put_string() reads freed ip_set_comment_rcu kmalloc memory—a classic UAF read usable for arbitrary kernel disclosure with heap grooming.\nI:H - Concurrent free and replacement of RCU-managed comment objects lets an attacker reclaim and control freed slab memory, providing standard paths to arbitrary kernel writes, metadata corruption, and control-flow hijack rather than a bounded or crash-only integrity effect.\nA:H - Stale comment pointer dereference during dump or subsequent slab reuse can immediately kernel-oops or panic the host, and the underlying UAF heap corruption can crash or hang the system even when full exploitation is not attempted." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/ipset/ip_set_core.c" ], "versions": [ { "version": "b57b2d1fa53fe8563bdfc66a33b844463b9af285", "lessThan": "c9787d7c24ffd83019f379455e1b97fb4f0f75eb", "status": "affected", "versionType": "git" }, { "version": "b57b2d1fa53fe8563bdfc66a33b844463b9af285", "lessThan": "6e98407cb94e035bba98956adc9096a76d8b2a9f", "status": "affected", "versionType": "git" }, { "version": "b57b2d1fa53fe8563bdfc66a33b844463b9af285", "lessThan": "50b70f56f3baaff46599f59b2d93fa2540120776", "status": "affected", "versionType": "git" }, { "version": "b57b2d1fa53fe8563bdfc66a33b844463b9af285", "lessThan": "d01b4b471f0fc5c396af62845e972ccf99cee29a", "status": "affected", "versionType": "git" }, { "version": "b57b2d1fa53fe8563bdfc66a33b844463b9af285", "lessThan": "fcb565966534909377a16be5f7b065db2e25c8b5", "status": "affected", "versionType": "git" }, { "version": "b57b2d1fa53fe8563bdfc66a33b844463b9af285", "lessThan": "8087bb360a936a6314d22b567e4b861656943eb6", "status": "affected", "versionType": "git" }, { "version": "b57b2d1fa53fe8563bdfc66a33b844463b9af285", "lessThan": "93a775fd67f3ef34949a9523bfa69403ee74efdd", "status": "affected", "versionType": "git" }, { "version": "b57b2d1fa53fe8563bdfc66a33b844463b9af285", "lessThan": "3ca9982a8882470aa0ac4e8bb9a552b181d1efcd", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/ipset/ip_set_core.c" ], "versions": [ { "version": "4.2", "status": "affected" }, { "version": "0", "lessThan": "4.2", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c9787d7c24ffd83019f379455e1b97fb4f0f75eb" }, { "url": "https://git.kernel.org/stable/c/6e98407cb94e035bba98956adc9096a76d8b2a9f" }, { "url": "https://git.kernel.org/stable/c/50b70f56f3baaff46599f59b2d93fa2540120776" }, { "url": "https://git.kernel.org/stable/c/d01b4b471f0fc5c396af62845e972ccf99cee29a" }, { "url": "https://git.kernel.org/stable/c/fcb565966534909377a16be5f7b065db2e25c8b5" }, { "url": "https://git.kernel.org/stable/c/8087bb360a936a6314d22b567e4b861656943eb6" }, { "url": "https://git.kernel.org/stable/c/93a775fd67f3ef34949a9523bfa69403ee74efdd" }, { "url": "https://git.kernel.org/stable/c/3ca9982a8882470aa0ac4e8bb9a552b181d1efcd" } ], "title": "netfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer()", "x_generator": { "engine": "bippy-1.2.0" } } } }