{"id":"CVE-2026-99239","title":"Bluetooth: L2CAP: refuse __l2cap_chan_add if chan already has conn","summary":"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_cha…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 8f90405a4a6f1f1880dc07996b47bf57c712bd8a < 85cc289eb08afa975375f838187369e68b429ee0","Linux >= 32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26b < 820579652b24ce277e0097cd65b42bd9b7b8bf07","Linux >= 8922c7940bae9ce4b1736dddb6362370793835c2 < e618d928ec7f88cbeadfa3542adcac40f474e629","Linux >= 91047a4396a8b1857a6f712a90cf33ec0012b189 < fabaff1c59ff2cc89cb7e5bd0186a5e15f0c73b2","Linux >= 0b0e2bf39cf99e458d991b9df253727e036a7d7d < 52fe88e4ef87311eee32b45c65603e7c69e75e7d","Linux >= d3b739db5dc6f688a60d56da872fabaf65246032 < 10c705dd706aa93164ba41f2566f15206d6c178e","Linux >= b66774b48dd98f07254951f74ea6f513efe7ff8b < 73820561d8cbfd3364a29b8fa77f1707f26029da","Linux >= b66774b48dd98f07254951f74ea6f513efe7ff8b < d3afd7803f9bc2a8c4270199497b60158b2fc647","Linux >= b66774b48dd98f07254951f74ea6f513efe7ff8b < 86b55991d3cd690e73c5ef8d20b75ae4905b357a","Linux 50c38d9f42a529691e4e67ea9cedf4f0bfc8d277","Linux >= 5.10.265 < 5.10.273","Linux >= 5.15.216 < 5.15.224","Linux >= 6.1.183 < 6.1.191","Linux >= 6.6.145 < 6.6.161","Linux >= 6.12.97 < 6.12.115","Linux >= 6.18.39 < 6.18.60","Linux >= 7.1.4 < 7.2","Linux 7.2"],"published":"2026-11-02","updated":"2026-11-03","sourceUpdated":"2026-11-03T19:13:06.554Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99239","references":[{"url":"https://git.kernel.org/stable/c/85cc289eb08afa975375f838187369e68b429ee0"},{"url":"https://git.kernel.org/stable/c/820579652b24ce277e0097cd65b42bd9b7b8bf07"},{"url":"https://git.kernel.org/stable/c/e618d928ec7f88cbeadfa3542adcac40f474e629"},{"url":"https://git.kernel.org/stable/c/fabaff1c59ff2cc89cb7e5bd0186a5e15f0c73b2"},{"url":"https://git.kernel.org/stable/c/52fe88e4ef87311eee32b45c65603e7c69e75e7d"},{"url":"https://git.kernel.org/stable/c/10c705dd706aa93164ba41f2566f15206d6c178e"},{"url":"https://git.kernel.org/stable/c/73820561d8cbfd3364a29b8fa77f1707f26029da"},{"url":"https://git.kernel.org/stable/c/d3afd7803f9bc2a8c4270199497b60158b2fc647"},{"url":"https://git.kernel.org/stable/c/86b55991d3cd690e73c5ef8d20b75ae4905b357a"}],"tags":["cve.org"],"epss":0.00126,"epssPercentile":0.02302,"ingestedAt":"2026-11-05T20:33:06.390Z","slug":"CVE-2026-99239","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 8f90405a4a6f1f1880dc07996b47bf57c712bd8a < 85cc289eb08afa975375f838187369e68b429ee0`\n- `Linux >= 32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26b < 820579652b24ce277e0097cd65b42bd9b7b8bf07`\n- `Linux >= 8922c7940bae9ce4b1736dddb6362370793835c2 < e618d928ec7f88cbeadfa3542adcac40f474e629`\n- `Linux >= 91047a4396a8b1857a6f712a90cf33ec0012b189 < fabaff1c59ff2cc89cb7e5bd0186a5e15f0c73b2`\n- `Linux >= 0b0e2bf39cf99e458d991b9df253727e036a7d7d < 52fe88e4ef87311eee32b45c65603e7c69e75e7d`\n- `Linux >= d3b739db5dc6f688a60d56da872fabaf65246032 < 10c705dd706aa93164ba41f2566f15206d6c178e`\n- `Linux >= b66774b48dd98f07254951f74ea6f513efe7ff8b < 73820561d8cbfd3364a29b8fa77f1707f26029da`\n- `Linux >= b66774b48dd98f07254951f74ea6f513efe7ff8b < d3afd7803f9bc2a8c4270199497b60158b2fc647`\n- `Linux >= b66774b48dd98f07254951f74ea6f513efe7ff8b < 86b55991d3cd690e73c5ef8d20b75ae4905b357a`\n- `Linux 50c38d9f42a529691e4e67ea9cedf4f0bfc8d277`\n- `Linux >= 5.10.265 < 5.10.273`\n- `Linux >= 5.15.216 < 5.15.224`\n- `Linux >= 6.1.183 < 6.1.191`\n- `Linux >= 6.6.145 < 6.6.161`\n- `Linux >= 6.12.97 < 6.12.115`\n- `Linux >= 6.18.39 < 6.18.60`\n- `Linux >= 7.1.4 < 7.2`\n- `Linux 7.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}