{"identifier":"CVE-2026-99239","cve":{"id":"CVE-2026-99239","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: refuse __l2cap_chan_add if chan already has conn\n\nl2cap_chan may be linked to l2cap_conn at most once. This is assumed in\nseveral places, eg l2cap_chan_del cleanup.\n\nThere is a TOCTOU race where the invariant is violated:\n\n    [Task 1]                          [Task 2]\n    l2cap_chan_connect                l2cap_sock_bind\n      l2cap_chan_lock                   lock_sock\n      l2cap_state_change                if (sk->sk_state != BT_OPEN)\n        chan->state = BT_CONNECT\n        l2cap_sock_state_change_cb      chan->state = BT_BOUND\n                                        sk->sk_state = BT_BOUND\n          lock_sock <------------------ release_sock\n          sk->sk_state = BT_CONNECT\n\nl2cap_sock_connect() does not check sk->sk_state, so since chan->state\nis now BT_BOUND, subsequent connect() ends up with second\n__l2cap_chan_add.\n\nExplicitly document and check the invariant in __l2cap_chan_add with\nWARN_ON_ONCE. The only callsite where it could be hit is\nl2cap_chan_connect, so add pre-check there to avoid relying on\nchan->state. chan->state read/write is not properly guarded currently so\nthere can be other TOCTOUC problems.\n\nAdd l2cap_lock_chan in l2cap_sock_bind() to guard chan->state write.","published":"2026-11-02T16:17:49.540000+00:00","modified":"2026-11-02T16:17:49.540000+00:00","status":"Received","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_version":"3.1","affected":[],"weaknesses":[],"references":[{"url":"https://git.kernel.org/stable/c/10c705dd706aa93164ba41f2566f15206d6c178e","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/52fe88e4ef87311eee32b45c65603e7c69e75e7d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/73820561d8cbfd3364a29b8fa77f1707f26029da","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/820579652b24ce277e0097cd65b42bd9b7b8bf07","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/85cc289eb08afa975375f838187369e68b429ee0","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d3afd7803f9bc2a8c4270199497b60158b2fc647","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e618d928ec7f88cbeadfa3542adcac40f474e629","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fabaff1c59ff2cc89cb7e5bd0186a5e15f0c73b2","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"kev":null,"kev_checked":true,"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[],"source":"nvd","retrieved_at":"2026-11-02T19:29:45.905346+00:00","exploited":false,"kev_stale":false,"products":[],"priority":{"label":"Assess exposure and vendor guidance","reasons":["No higher-priority signal is available in the current stored evidence.","Fresh EPSS data is unavailable; missing values are not zero."]},"epss":null,"version_assessment":null},"news":[],"campaigns":[],"domains":[{"domain":"git.kernel.org","source_url":"https://git.kernel.org/stable/c/10c705dd706aa93164ba41f2566f15206d6c178e","investigate_url":"https://investigate.aeglixmind.com/#git.kernel.org"}],"arsenal_url":"https://arsenal.aeglixmind.com/?cve=CVE-2026-99239","catalog_url":"https://cves.aeglixmind.com/cve/CVE-2026-99239","research_url":"https://investigate.aeglixmind.com/research/cve/CVE-2026-99239","coverage":{"news_candidates_checked":0,"campaign_candidates_checked":0,"bounded":false,"notice":"Exact CVE mentions in stored public excerpts and reviewed campaign content only. A mention is not proof of exploitation, attribution or tool suitability. Missing matches do not establish absence."}}