{"id":"CVE-2025-39889","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: l2cap: Check encryption key size on incoming connection\n\nThis is required for passing GAP/SEC/SEM/BI-04-C PTS test case:\n  Security Mode 4 Level 4, Responder…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: l2cap: Check encryption key size on incoming connection\n\nThis is required for passing GAP/SEC/SEM/BI-04-C PTS test case:\n  Security Mode 4 Level 4, Responder…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-326","CWE-326"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.11, < 5.15.181","linux_kernel >= 5.16, < 6.1.135","linux_kernel >= 6.2, < 6.6.88","linux_kernel >= 6.7, < 6.12.25","linux_kernel >= 6.13, < 6.14.4","linux_kernel = 6.15"],"patched":["linux_kernel 6.14.4"],"published":"2025-09-24","updated":"2026-09-26","sourceUpdated":"2026-09-26T00:10:00.127","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-39889","references":[{"url":"https://git.kernel.org/stable/c/24b2cdfc16e9bd6ab3d03b8e01c590755bd3141f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/522e9ed157e3c21b4dd623c79967f72c21e45b78","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9e3114958d87ea88383cbbf38c89e04b8ea1bce5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c6d527bbd3d3896375079f5dbc8b7f96734a3ba5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d49798ecd26e0ee7995a7fc1e90ca5cd9b4402d6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d4ca2fd218caafbf50e3343ba1260c6a23b5676a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ed503d340a501e414114ddc614a3aae4f6e9eae2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00096,"epssPercentile":0.0067,"ingestedAt":"2026-09-26T00:22:39.950Z","slug":"CVE-2025-39889","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: l2cap: Check encryption key size on incoming connection\n\nThis is required for passing GAP/SEC/SEM/BI-04-C PTS test case:\n  Security Mode 4 Level 4, Responder - Invalid Encryption Key Size\n  - 128 bit\n\nThis tests the security key with size from 1 to 15 bytes while the\nSecurity Mode 4 Level 4 requests 16 bytes key size.\n\nCurrently PTS fails with the following logs:\n- expected:Connection Response:\n    Code: [3 (0x03)] Code\n    Identifier: (lt)WildCard: Exists(gt)\n    Length: [8 (0x0008)]\n    Destination CID: (lt)WildCard: Exists(gt)\n    Source CID: [64 (0x0040)]\n    Result: [3 (0x0003)] Connection refused - Security block\n    Status: (lt)WildCard: Exists(gt),\nbut received:Connection Response:\n    Code: [3 (0x03)] Code\n    Identifier: [1 (0x01)]\n    Length: [8 (0x0008)]\n    Destination CID: [64 (0x0040)]\n    Source CID: [64 (0x0040)]\n    Result: [0 (0x0000)] Connection Successful\n    Status: [0 (0x0000)] No further information available\n\nAnd HCI logs:\n< HCI Command: Read Encrypti.. (0x05|0x0008) plen 2\n        Handle: 14 Address: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.)\n> HCI Event: Command Complete (0x0e) plen 7\n      Read Encryption Key Size (0x05|0x0008) ncmd 1\n        Status: Success (0x00)\n        Handle: 14 Address: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.)\n        Key size: 7\n> ACL Data RX: Handle 14 flags 0x02 dlen 12\n      L2CAP: Connection Request (0x02) ident 1 len 4\n        PSM: 4097 (0x1001)\n        Source CID: 64\n< ACL Data TX: Handle 14 flags 0x00 dlen 16\n      L2CAP: Connection Response (0x03) ident 1 len 8\n        Destination CID: 64\n        Source CID: 64\n        Result: Connection successful (0x0000)\n        Status: No further information available (0x0000)\n\n## Affected\n\n- `linux_kernel >= 5.11, < 5.15.181`\n- `linux_kernel >= 5.16, < 6.1.135`\n- `linux_kernel >= 6.2, < 6.6.88`\n- `linux_kernel >= 6.7, < 6.12.25`\n- `linux_kernel >= 6.13, < 6.14.4`\n- `linux_kernel = 6.15`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.14.4`","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}