{"cve":"CVE-2026-64404","nvd":{"published":"2026-07-25T10:17:24.003","modified":"2026-09-04T14:25:04.877","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: avoid NULL deref of conn in iso_conn_big_sync()\n\niso_conn_big_sync() drops the socket lock to call hci_get_route() and\nthen re-acquires it, but dereferences iso_pi(sk)->conn->hcon afterwards\nwithout re-checking that conn is still valid.\n\nWhile the lock is dropped, the connection can be torn down under the\nsame socket lock: iso_disconn_cfm() -> iso_conn_del() -> iso_chan_del()\nsets iso_pi(sk)->conn to NULL (and the broadcast teardown path can also\nclear conn->hcon on its own). When iso_conn_big_sync() re-acquires the\nlock and reads conn->hcon, conn may be NULL, causing a NULL pointer\ndereference (hcon is the first member of struct iso_conn).\n\nThis path is reached from iso_sock_recvmsg() for a PA-sync broadcast\nsink socket (BT_SK_DEFER_SETUP | BT_SK_PA_SYNC), so the dropped-lock\nwindow can race with connection teardown driven by controller events.\n\nRe-validate iso_pi(sk)->conn and its hcon after re-acquiring the socket\nlock and bail out if the connection went away, as already done in the\nsibling iso_sock_rebind_bc().","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/01afd198c2c286cd3b81f44d4e33a2e638711550","https://git.kernel.org/stable/c/b3e647a4aa4d2d054f86a783f5c426035e1dc237","https://git.kernel.org/stable/c/b84eeb7636d6962dd882d5e0b31475e4f404313c","https://git.kernel.org/stable/c/d5541eb148da72d5e0a1bca8ecd171f9fc8b366f"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:46:40.600842820+00:00"},"epss":{"cve":"CVE-2026-64404","score":0.00122,"percentile":0.01963,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}