{"id":"CVE-2026-10660","revision":"792fa50570464e6b9142791bfab70f3f","records":[{"revision":"792fa50570464e6b9142791bfab70f3f","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-10660","aliases":[],"title":"Shared reassembly buffer in Bluetooth BAP Broadcast Assistant enables cross-connection memory corruption","description":"The Bluetooth BAP Broadcast Assistant GATT client in subsys/bluetooth/audio/bap_broadcast_assistant.c reassembled remote Broadcast Receive State data into a single file-static net_buf_simple (att_buf, BT_ATT_MAX_ATTRIBUTE_LEN = 512 bytes) shared by all connection instances, while the BUSY flag, long-read handle, and reset/offset state were per-connection.\n\nWhen the device acts as a Broadcast Assistant connected to multiple Scan Delegator peripherals, notification and long-read callbacks from different connections interleave on the shared buffer: the append in notify_handler (net_buf_simple_add_mem at the not-busy branch) performs no tailroom check, so receive-state notifications from two or more delegators accumulate on the same 512-byte buffer and, with a sufficiently large configured ATT MTU (BT_L2CAP_TX_MTU up to 2000) and two-to-three concurrent connections, write past the buffer into adjacent .bss (net_buf_simple_add only asserts in debug builds).\n\nEven below the overflow threshold, one connection's net_buf_simple_reset zeroes the shared length while another connection's reassembly and GATT read offset are in flight, mixing one peer's data into another's parse. A malicious or compromised Scan Delegator (or two colluding peers) over BLE can trigger this, causing out-of-bounds writes (memory corruption / denial of service) and cross-connection data corruption.\n\nThe fix moves the buffer into the per-connection instance struct so each connection reassembles into its own buffer. Affects Zephyr releases shipping the Broadcast Assistant with the shared buffer, including v4.4.0 and earlier.","state":0,"publishedAt":"2026-07-11T17:00:13.644+00:00","modifiedAt":"2026-10-15T22:10:10.77+00:00","affected":[{"ecosystem":"https://github.com/zephyrproject-rtos/zephyr","name":"zephyr","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"collectionURL\": \"https://github.com/zephyrproject-rtos/zephyr\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageName\": \"zephyr\",\n                    \"product\": \"zephyr\",\n                    \"programFiles\": [\n                        \"subsys/bluetooth/audio/bap_broadcast_assistant.c\"\n                    ],\n                    \"vendor\": \"zephyrproject\",\n                    \"versions\": [\n                        {\n                            \"lessThan\": \"4.3.1\",\n                            \"status\": \"affected\",\n                            \"version\": \"3.6.0\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"lessThan\": \"4.4.2\",\n                            \"status\": \"affected\",\n                            \"version\": \"4.4.0\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","score":6.4,"severity":"MEDIUM"}],"references":["https://github.com/zephyrproject-rtos/zephyr/commit/0cd61589ff820b6a585c73cb36f1e14b043a2795","https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-73c7-3rh7-v5p9"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-10660","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-10660","identifiers":["CVE-2026-10660"]},"retained":false,"historicalAffected":[]}],"coverage":[]}