{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23458","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-01-13T15:37:46.021Z","datePublished":"2026-04-03T15:15:39.041Z","dateUpdated":"2026-05-11T22:07:22.715Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T22:07:22.715Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: fix use-after-free in ctnetlink_dump_exp_ct()\n\nctnetlink_dump_exp_ct() stores a conntrack pointer in cb->data for the\nnetlink dump callback ctnetlink_exp_ct_dump_table(), but drops the\nconntrack reference immediately after netlink_dump_start().  When the\ndump spans multiple rounds, the second recvmsg() triggers the dump\ncallback which dereferences the now-freed conntrack via nfct_help(ct),\nleading to a use-after-free on ct->ext.\n\nThe bug is that the netlink_dump_control has no .start or .done\ncallbacks to manage the conntrack reference across dump rounds.  Other\ndump functions in the same file (e.g. ctnetlink_get_conntrack) properly\nuse .start/.done callbacks for this purpose.\n\nFix this by adding .start and .done callbacks that hold and release the\nconntrack reference for the duration of the dump, and move the\nnfct_help() call after the cb->args[0] early-return check in the dump\ncallback to avoid dereferencing ct->ext unnecessarily.\n\n BUG: KASAN: slab-use-after-free in ctnetlink_exp_ct_dump_table+0x4f/0x2e0\n Read of size 8 at addr ffff88810597ebf0 by task ctnetlink_poc/133\n\n CPU: 1 UID: 0 PID: 133 Comm: ctnetlink_poc Not tainted 7.0.0-rc2+ #3 PREEMPTLAZY\n Call Trace:\n  <TASK>\n  ctnetlink_exp_ct_dump_table+0x4f/0x2e0\n  netlink_dump+0x333/0x880\n  netlink_recvmsg+0x3e2/0x4b0\n  ? aa_sk_perm+0x184/0x450\n  sock_recvmsg+0xde/0xf0\n\n Allocated by task 133:\n  kmem_cache_alloc_noprof+0x134/0x440\n  __nf_conntrack_alloc+0xa8/0x2b0\n  ctnetlink_create_conntrack+0xa1/0x900\n  ctnetlink_new_conntrack+0x3cf/0x7d0\n  nfnetlink_rcv_msg+0x48e/0x510\n  netlink_rcv_skb+0xc9/0x1f0\n  nfnetlink_rcv+0xdb/0x220\n  netlink_unicast+0x3ec/0x590\n  netlink_sendmsg+0x397/0x690\n  __sys_sendmsg+0xf4/0x180\n\n Freed by task 0:\n  slab_free_after_rcu_debug+0xad/0x1e0\n  rcu_core+0x5c3/0x9c0"}],"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"}}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_conntrack_netlink.c"],"versions":[{"version":"e844a928431fa8f1359d1f4f2cef53d9b446bf52","lessThan":"d8cd0efbccc5cfb0a80da744a7da76e1333ab925","status":"affected","versionType":"git"},{"version":"e844a928431fa8f1359d1f4f2cef53d9b446bf52","lessThan":"9821b47f669eb82791fa0b1a6ebaf9aa219bea72","status":"affected","versionType":"git"},{"version":"e844a928431fa8f1359d1f4f2cef53d9b446bf52","lessThan":"bdf2724eefd4455a66863abb025bab8d3aa98c57","status":"affected","versionType":"git"},{"version":"e844a928431fa8f1359d1f4f2cef53d9b446bf52","lessThan":"f04cc86d59906513d2d62183b882966fc0ae0390","status":"affected","versionType":"git"},{"version":"e844a928431fa8f1359d1f4f2cef53d9b446bf52","lessThan":"f025171feef2ac65663d7986f1d5ff0c28d6b2a9","status":"affected","versionType":"git"},{"version":"e844a928431fa8f1359d1f4f2cef53d9b446bf52","lessThan":"04c8907ce4e3d3e26c5e1a3e47aa5d17082cbb56","status":"affected","versionType":"git"},{"version":"e844a928431fa8f1359d1f4f2cef53d9b446bf52","lessThan":"cd541f15b60e2257441398cf495d978f816d09f8","status":"affected","versionType":"git"},{"version":"e844a928431fa8f1359d1f4f2cef53d9b446bf52","lessThan":"5cb81eeda909dbb2def209dd10636b51549a3f8a","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/nf_conntrack_netlink.c"],"versions":[{"version":"3.10","status":"affected"},{"version":"0","lessThan":"3.10","status":"unaffected","versionType":"semver"},{"version":"5.10.253","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.203","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.167","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.130","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.78","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.20","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19.10","lessThanOrEqual":"6.19.*","status":"unaffected","versionType":"semver"},{"version":"7.0","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":"3.10","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.1.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.6.130"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.12.78"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.18.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"6.19.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10","versionEndExcluding":"7.0"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/d8cd0efbccc5cfb0a80da744a7da76e1333ab925"},{"url":"https://git.kernel.org/stable/c/9821b47f669eb82791fa0b1a6ebaf9aa219bea72"},{"url":"https://git.kernel.org/stable/c/bdf2724eefd4455a66863abb025bab8d3aa98c57"},{"url":"https://git.kernel.org/stable/c/f04cc86d59906513d2d62183b882966fc0ae0390"},{"url":"https://git.kernel.org/stable/c/f025171feef2ac65663d7986f1d5ff0c28d6b2a9"},{"url":"https://git.kernel.org/stable/c/04c8907ce4e3d3e26c5e1a3e47aa5d17082cbb56"},{"url":"https://git.kernel.org/stable/c/cd541f15b60e2257441398cf495d978f816d09f8"},{"url":"https://git.kernel.org/stable/c/5cb81eeda909dbb2def209dd10636b51549a3f8a"}],"title":"netfilter: ctnetlink: fix use-after-free in ctnetlink_dump_exp_ct()","x_generator":{"engine":"bippy-1.2.0"}}}}