{"id":"CVE-2026-72434","state":"PUBLISHED","title":"netfilter: ipset: make sure gc is properly stopped","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ipset: make sure gc is properly stopped\n\nSashiko noticed that when destroying a set,\ncancel_delayed_work_sync() was called while gc\ncalls queue_delayed_work() unconditionally which\ncan lead not to properly shutting down the gc.","publishedAt":"2026-08-15T05:56:48.756Z","updatedAt":"2026-10-16T18:55:23.726Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f66ee0410b1c3481ee75e5db9b34547b4d582465","status":"affected","lessThan":"c940d1b96248c3081b664ede5418078bdc7c8c07","versionType":"git"},{"version":"f66ee0410b1c3481ee75e5db9b34547b4d582465","status":"affected","lessThan":"12088da6add5b003657c8506c5b0fcef835083b8","versionType":"git"},{"version":"f66ee0410b1c3481ee75e5db9b34547b4d582465","status":"affected","lessThan":"c78bd5195a5998094a5866df702fbeafda60dafb","versionType":"git"},{"version":"f66ee0410b1c3481ee75e5db9b34547b4d582465","status":"affected","lessThan":"4a597a87e2e2f608edb6be2c510dc826b4fdfb53","versionType":"git"},{"version":"5dd9488ae41070b69d2f4acb580f77db5705f9ca","status":"affected","versionType":"git"},{"version":"a469bab3386aebff33c59506f3a95e35b91118fd","status":"affected","versionType":"git"},{"version":"5.4.24","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"5.5.8","status":"affected","lessThan":"5.6","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/ipset/ip_set_hash_gen.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","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/ipset/ip_set_hash_gen.h"]}],"references":["https://git.kernel.org/stable/c/c940d1b96248c3081b664ede5418078bdc7c8c07","https://git.kernel.org/stable/c/12088da6add5b003657c8506c5b0fcef835083b8","https://git.kernel.org/stable/c/c78bd5195a5998094a5866df702fbeafda60dafb","https://git.kernel.org/stable/c/4a597a87e2e2f608edb6be2c510dc826b4fdfb53"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72434.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72434","state":"PUBLISHED","datePublished":"2026-08-15T05:56:48.756Z","dateUpdated":"2026-10-16T18:55:23.726Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.929Z"},"containers":{"cna":{"title":"netfilter: ipset: make sure gc is properly stopped","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ipset: make sure gc is properly stopped\n\nSashiko noticed that when destroying a set,\ncancel_delayed_work_sync() was called while gc\ncalls queue_delayed_work() unconditionally which\ncan lead not to properly shutting down the gc."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f66ee0410b1c3481ee75e5db9b34547b4d582465","status":"affected","lessThan":"c940d1b96248c3081b664ede5418078bdc7c8c07","versionType":"git"},{"version":"f66ee0410b1c3481ee75e5db9b34547b4d582465","status":"affected","lessThan":"12088da6add5b003657c8506c5b0fcef835083b8","versionType":"git"},{"version":"f66ee0410b1c3481ee75e5db9b34547b4d582465","status":"affected","lessThan":"c78bd5195a5998094a5866df702fbeafda60dafb","versionType":"git"},{"version":"f66ee0410b1c3481ee75e5db9b34547b4d582465","status":"affected","lessThan":"4a597a87e2e2f608edb6be2c510dc826b4fdfb53","versionType":"git"},{"version":"5dd9488ae41070b69d2f4acb580f77db5705f9ca","status":"affected","versionType":"git"},{"version":"a469bab3386aebff33c59506f3a95e35b91118fd","status":"affected","versionType":"git"},{"version":"5.4.24","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"5.5.8","status":"affected","lessThan":"5.6","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/ipset/ip_set_hash_gen.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","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/ipset/ip_set_hash_gen.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/c940d1b96248c3081b664ede5418078bdc7c8c07"},{"url":"https://git.kernel.org/stable/c/12088da6add5b003657c8506c5b0fcef835083b8"},{"url":"https://git.kernel.org/stable/c/c78bd5195a5998094a5866df702fbeafda60dafb"},{"url":"https://git.kernel.org/stable/c/4a597a87e2e2f608edb6be2c510dc826b4fdfb53"}],"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 via NFNETLINK ipset destroy/cleanup (IPSET_CMD_DESTROY or netns exit calling cancel_gc), not by processing remote packets; all entry points are local netlink syscalls into net/netfilter/ipset.\nAC:L - An attacker with CAP_NET_ADMIN creates a timeout hash ipset, waits for the workqueue GC to run, then destroys the set; because mtype_gc always re-queues itself at the end of execution, cancel_delayed_work_sync reliably leaves a pending GC after teardown.\nPR:L - All ipset management, including set destroy that calls mtype_cancel_gc, requires CAP_NET_ADMIN checked by netlink_net_capable in nfnetlink; unprivileged users can obtain this in an isolated user+network namespace via unshare -Urn.\nUI:N - Exploitation is fully automated through netlink ipset create/destroy commands and does not require any victim user action such as mounting filesystems or opening files.\nS:U - The use-after-free corrupts kernel heap memory within the same host kernel security boundary; it does not by itself cross VM, container runtime, or IOMMU isolation boundaries.\nC:H - After teardown, the orphaned GC work dereferences freed ip_set and htype structures (including embedded delayed_work), a classic slab UAF that enables heap grooming and arbitrary kernel memory disclosure.\nI:H - UAF on ipset hash control structures and hbucket data allows corrupting freed heap objects and building write primitives for control-flow hijacking and local privilege escalation beyond the caller's namespace.\nA:H - Dereferencing freed set, htype, and hash table memory from the GC workqueue can immediately trigger kernel oopses or panics, and the bug is repeatable on every destroy of a timeout hash 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ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-72434","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:49:50.650584Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:55:23.726Z"}}]}}}