{ "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": "2026-08-05T12:21:57.345Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:21:57.345Z" }, "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 \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" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is reached through a local NETLINK_NETFILTER ctnetlink request, specifically an expectation dump with CTA_EXPECT_MASTER. It is not reachable directly from unauthenticated network packets.\nAC:L - The attacker can create the relevant conntrack/expectation state, start the multipart dump, and free the master conntrack before the next recvmsg. No condition outside attacker control or difficult race is required.\nPR:L - nfnetlink requires CAP_NET_ADMIN, but the check is against the socket network namespace and is reachable by an unprivileged user via user and network namespaces. This makes the required privilege low rather than high.\nUI:N - Exploitation is driven entirely by attacker-issued netlink operations. No victim user action is required.\nS:U - The impact is within the kernel and the same local system security authority. This is a standard local kernel memory-corruption issue, not a cross-scope boundary escape such as guest-to-host.\nC:H - The bug is a use-after-free of a conntrack object and its extension pointer during a netlink dump. A freed kernel object can plausibly be reclaimed and shaped for information disclosure, so confidentiality impact is high.\nI:H - Use-after-free in kernel heap memory can plausibly be leveraged beyond a crash into memory corruption or control-flow manipulation. Following the required conservative scoring, integrity impact is high.\nA:H - The reported failure is a KASAN slab-use-after-free in kernel netlink dump handling and can cause an oops or panic. The attacker can trigger it repeatedly through local netlink requests." } ] } ], "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" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:47:16.594Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": 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