{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23169", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.982Z", "datePublished": "2026-02-14T16:01:32.139Z", "dateUpdated": "2026-08-05T12:20:24.946Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:20:24.946Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix race in mptcp_pm_nl_flush_addrs_doit()\n\nsyzbot and Eulgyu Kim reported crashes in mptcp_pm_nl_get_local_id()\nand/or mptcp_pm_nl_is_backup()\n\nRoot cause is list_splice_init() in mptcp_pm_nl_flush_addrs_doit()\nwhich is not RCU ready.\n\nlist_splice_init_rcu() can not be called here while holding pernet->lock\nspinlock.\n\nMany thanks to Eulgyu Kim for providing a repro and testing our patches." } ], "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 vulnerability requires a local attacker to send a netlink MPTCP_PM_CMD_FLUSH_ADDRS command, which requires CAP_NET_ADMIN (accessible via user namespaces but still local access). The RCU reader side can be triggered by network MPTCP connections, but the flush side requires local netlink access.\nAC:L - The attacker controls both sides of the race — they can issue the netlink flush command while simultaneously establishing MPTCP connections that trigger RCU list traversal. Since the attacker creates and controls the race condition, complexity is low.\nPR:L - The flush_addrs netlink operation uses GENL_UNS_ADMIN_PERM, which checks CAP_NET_ADMIN in the user namespace via netlink_ns_capable(). An unprivileged user can obtain this capability through user namespaces (unshare -Urn).\nUI:N - No user interaction is required. The attacker can trigger both the netlink flush and the MPTCP connection processing independently without any victim action.\nS:U - The vulnerability exists within the kernel and impacts the same security context. There is no crossing of a virtualization or sandbox boundary.\nC:H - This is a use-after-free / list corruption bug where RCU readers access freed mptcp_pm_addr_entry structures. UAF gives the attacker control over freed object contents via heap spraying, enabling arbitrary kernel memory reads.\nI:H - The use-after-free on mptcp_pm_addr_entry structures (which contain function-relevant pointers and a socket pointer) can be exploited via heap spraying to achieve arbitrary write primitives and potentially control flow hijacking.\nA:H - The corrupted list pointers and use-after-free reliably cause kernel crashes (oops/panic) as reported by syzbot, providing a straightforward denial-of-service vector." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/mptcp/pm_kernel.c" ], "versions": [ { "version": "141694df6573b49aa4143c92556544b4b0bbda72", "lessThan": "338d40bab283da2639780ee3e458fb61f1567d8c", "status": "affected", "versionType": "git" }, { "version": "141694df6573b49aa4143c92556544b4b0bbda72", "lessThan": "7896dbe990d56d5bb8097863b2645355633665eb", "status": "affected", "versionType": "git" }, { "version": "141694df6573b49aa4143c92556544b4b0bbda72", "lessThan": "455e882192c9833f176f3fbbbb2f036b6c5bf555", "status": "affected", "versionType": "git" }, { "version": "141694df6573b49aa4143c92556544b4b0bbda72", "lessThan": "51223bdd0f60b06cfc7f25885c4d4be917adba94", "status": "affected", "versionType": "git" }, { "version": "141694df6573b49aa4143c92556544b4b0bbda72", "lessThan": "1f1b9523527df02685dde603f20ff6e603d8e4a1", "status": "affected", "versionType": "git" }, { "version": "141694df6573b49aa4143c92556544b4b0bbda72", "lessThan": "e2a9eeb69f7d4ca4cf4c70463af77664fdb6ab1d", "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/mptcp/pm_kernel.c" ], "versions": [ { "version": "5.11", "status": "affected" }, { "version": "0", "lessThan": "5.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.201", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.164", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.125", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.72", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.9", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "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": "5.11", "versionEndExcluding": "5.15.201" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.1.164" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.6.125" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.12.72" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.18.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/338d40bab283da2639780ee3e458fb61f1567d8c" }, { "url": "https://git.kernel.org/stable/c/7896dbe990d56d5bb8097863b2645355633665eb" }, { "url": "https://git.kernel.org/stable/c/455e882192c9833f176f3fbbbb2f036b6c5bf555" }, { "url": "https://git.kernel.org/stable/c/51223bdd0f60b06cfc7f25885c4d4be917adba94" }, { "url": "https://git.kernel.org/stable/c/1f1b9523527df02685dde603f20ff6e603d8e4a1" }, { "url": "https://git.kernel.org/stable/c/e2a9eeb69f7d4ca4cf4c70463af77664fdb6ab1d" } ], "title": "mptcp: fix race in mptcp_pm_nl_flush_addrs_doit()", "x_generator": { "engine": "bippy-1.2.0" } } } }