{"id":"CVE-2026-98457","title":"Bluetooth: L2CAP: validate frame length before control and FCS access","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: validate frame length before control and FCS access\n\nl2cap_data_rcv() unpacks either a two-byte or four-byte control field\nwithout first ensuring that…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 4373ba79a267947e771c438507f7b103e30bdb21","Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 965bd88ed4b4763cb765dd65885adcfa588c6b14","Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 3acf6a0038ec0d4e8f4dcbfc2a557dff5f61cb70","Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 8c7556c7cd17e073bbefdc4a9a4694a207544c37","Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 1fdbb2a712a9a162ee817c959740face80b3d929","Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < c6a288e6001bcce16553c3853e0f5a45eaaf85c7","Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < f557274af7b94b6134692e6f26b880f1e34c15bf","Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 6c78a213d9070b610c7f418af2c25b66180b7e37","Linux 2.6.32"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:15:06.718Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98457","references":[{"url":"https://git.kernel.org/stable/c/4373ba79a267947e771c438507f7b103e30bdb21"},{"url":"https://git.kernel.org/stable/c/965bd88ed4b4763cb765dd65885adcfa588c6b14"},{"url":"https://git.kernel.org/stable/c/3acf6a0038ec0d4e8f4dcbfc2a557dff5f61cb70"},{"url":"https://git.kernel.org/stable/c/8c7556c7cd17e073bbefdc4a9a4694a207544c37"},{"url":"https://git.kernel.org/stable/c/1fdbb2a712a9a162ee817c959740face80b3d929"},{"url":"https://git.kernel.org/stable/c/c6a288e6001bcce16553c3853e0f5a45eaaf85c7"},{"url":"https://git.kernel.org/stable/c/f557274af7b94b6134692e6f26b880f1e34c15bf"},{"url":"https://git.kernel.org/stable/c/6c78a213d9070b610c7f418af2c25b66180b7e37"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.304Z","slug":"CVE-2026-98457","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: validate frame length before control and FCS access\n\nl2cap_data_rcv() unpacks either a two-byte or four-byte control field\nwithout first ensuring that it is present. A short ERTM or streaming-mode\nframe can therefore cause an out-of-bounds read.\n\nThere is a second short-frame case when CRC16 is enabled. After the\ncontrol field is pulled, l2cap_check_fcs() subtracts two from skb->len\nwithout checking it. If fewer than two bytes remain, the subtraction\nwraps; skb_trim() leaves the buffer unchanged and the subsequent FCS\nload reads past the logical end of the frame.\n\nValidate that the frame contains both its control field and, when\nenabled, its FCS before either field is accessed.\n\n## Affected\n\n- `Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 4373ba79a267947e771c438507f7b103e30bdb21`\n- `Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 965bd88ed4b4763cb765dd65885adcfa588c6b14`\n- `Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 3acf6a0038ec0d4e8f4dcbfc2a557dff5f61cb70`\n- `Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 8c7556c7cd17e073bbefdc4a9a4694a207544c37`\n- `Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 1fdbb2a712a9a162ee817c959740face80b3d929`\n- `Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < c6a288e6001bcce16553c3853e0f5a45eaaf85c7`\n- `Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < f557274af7b94b6134692e6f26b880f1e34c15bf`\n- `Linux >= 1c2acffb76d4bc5fd27c4ea55cc27ad8ead10f9a < 6c78a213d9070b610c7f418af2c25b66180b7e37`\n- `Linux 2.6.32`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}