{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-99122", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.393Z", "datePublished": "2026-10-28T10:34:37.859Z", "dateUpdated": "2026-10-31T12:43:23.512Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-31T12:43:23.512Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: validate packet source for connected sockets\n\nvmci_transport_recv_stream_cb() looks up sockets first by the full source\nand destination tuple, then by destination only in the bound table. The\nfallback can select a non-listening socket without checking whether the\npacket came from its stored peer.\n\nThis was reproduced with two VMCI contexts. A RST from the context not\nstored in a TCP_SYN_SENT socket reset that socket after it was selected by\nthe destination-only lookup.\n\nVMCI can process notification packets in bottom-half context when the\nsocket is not owned by user context, or defer packets to a workqueue. Use\nvsock_check_source() after taking the socket lock in the bottom-half path,\nand recheck after lock_sock() in the workqueue path. Listening sockets\ncontinue to accept packets from any source.\n\nReply with a RST addressed from the received packet before dropping a\nsource that fails validation. This preserves the existing reset behavior\nfor bound non-listening and concurrently closed sockets without directing\nthe reset to a connected socket's stored peer." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:H", "baseScore": 7.3, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - A local VMCI endpoint supplies the forged control datagram through IOCTL_VMCI_DATAGRAM_SEND, reaching vmci_datagram_dispatch() and the patched vmci_transport_recv_stream_cb(); vsock is therefore Local rather than a routable network vector.\nAC:L - vsock_diag_dump() exposes socket CIDs, ports, and state without an authorization check, after which a chosen RST deterministically misses vsock_find_connected_socket() and reaches the victim through vsock_find_bound_socket(); no race or uncontrolled condition is required.\nPR:L - vmci_host_open(), IOCTL_VMCI_INIT_CONTEXT, and IOCTL_VMCI_DATAGRAM_SEND contain no capability check, allowing a low-privilege VMX/local process with ordinary VMCI-device access to create an unrestricted context and submit the packet.\nUI:N - After the victim process has an ordinary bound connecting or established socket, the attacker's datagram alone drives vmci_transport_recv_pkt_work() and the reset handler; no victim user action is required.\nS:C - A packet owned by an attacker-controlled guest/VMX VMCI context is applied to a host-context socket by vmci_transport_recv_connecting_client() or vmci_transport_recv_connected(), crossing the VMCI virtualization or VMM-sandbox boundary.\nC:L - On an established socket, a forged WAITING_READ reaches vmci_transport_handle_waiting_read(), which conditionally returns WROTE to the foreign source based on vmci_qpair_produce_buf_ready(); this exposes limited queue-occupancy and traffic-state information, not payload bytes.\nI:N - The demonstrated RST and forged notification paths do not write application payloads, alter the intended VMCI queue pair, or corrupt memory; their changes to sk_state, peer_shutdown, and notification flags implement connection disruption rather than data modification.\nA:H - vmci_transport_recv_connecting_client() sets TCP_CLOSE and ECONNRESET, while vmci_transport_recv_connected() sets SOCK_DONE, SHUTDOWN_MASK, and TCP_CLOSING. Because tuples can be re-enumerated and RST injection repeated, the attacker can continuously terminate targeted VMCI client connections and fully deny their service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/vmw_vsock/vmci_transport.c" ], "versions": [ { "version": "d021c344051af91f42c5ba9fdedc176740cbd238", "lessThan": "c027f8b429dbb2157fc1b503df196e272d947c89", "status": "affected", "versionType": "git" }, { "version": "d021c344051af91f42c5ba9fdedc176740cbd238", "lessThan": "90c423b62ec9be08177f74b07a47937ca8d2035b", "status": "affected", "versionType": "git" }, { "version": "d021c344051af91f42c5ba9fdedc176740cbd238", "lessThan": "ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7", "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/vmw_vsock/vmci_transport.c" ], "versions": [ { "version": "3.9", "status": "affected" }, { "version": "0", "lessThan": "3.9", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.59", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.13", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "3.9", "versionEndExcluding": "6.18.59" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.9", "versionEndExcluding": "7.2.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.9", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c027f8b429dbb2157fc1b503df196e272d947c89" }, { "url": "https://git.kernel.org/stable/c/90c423b62ec9be08177f74b07a47937ca8d2035b" }, { "url": "https://git.kernel.org/stable/c/ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7" } ], "title": "vsock/vmci: validate packet source for connected sockets", "x_generator": { "engine": "bippy-1.2.0" } } } }