{"id":"CVE-2026-80760","summary":"Bluetooth: MGMT: reject HCI_CMD_SYNC params_len above 255","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: MGMT: reject HCI_CMD_SYNC params_len above 255\n\nmgmt_hci_cmd_sync() checks that the message length agrees with params_len\nbut puts no upper bound on it. params_len is __le16 while the parameter\nlength in the HCI command header is a u8:\n\n\tstruct hci_command_hdr {\n\t\t__le16\topcode;\n\t\t__u8\tplen;\n\t} __packed;\n\nhci_cmd_sync_alloc() assigns one to the other:\n\n\thdr-\u003eplen = plen;\n\n\tif (plen)\n\t\tskb_put_data(skb, param, plen);\n\nso a params_len of 256 leaves plen at 0 while all 256 bytes are still\nappended. The frame handed to the driver then declares no parameters and\ncarries 256 of them. On a length framed transport such as H:4 the\ncontroller takes the trailing bytes as the start of the next packet.\n\nThe mgmt socket MTU is HCI_MAX_FRAME_SIZE, so params_len can reach about\n1KB this way. Commit 03f1700b9b4d (\"Bluetooth: MGMT: reject malformed\nHCI_CMD_SYNC commands\") only made params_len agree with the message\nlength, a value that fits the message but not the header field is still\naccepted.\n\nReject params_len that does not fit the header field.","modified":"2026-09-06T03:46:45.357958395Z","published":"2026-09-04T15:12:32.306Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80760.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0bd0195ce25737cbdd0eabc54319ee0ddf3a0ad2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5d95286b6d6e8f1d304da7522bfa6860fc017e48"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6e1c44878aa3ee7336efeaf01414b030b0a5c273"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b7d9edcf9fe6e9ec3a2e80ef9e8d44ef9b4f2894"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80760.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80760"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"827af4787e74e8df9e8e0677a69fbb15e0856d2f"},{"fixed":"b7d9edcf9fe6e9ec3a2e80ef9e8d44ef9b4f2894"},{"fixed":"0bd0195ce25737cbdd0eabc54319ee0ddf3a0ad2"},{"fixed":"6e1c44878aa3ee7336efeaf01414b030b0a5c273"},{"fixed":"5d95286b6d6e8f1d304da7522bfa6860fc017e48"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80760.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.47"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.11"}]},{"type":"ECOSYSTEM","events":[{"introduced":"7.2.0"},{"fixed":"7.2.1"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80760.json"}}],"schema_version":"1.9.0"}