{"cve":"CVE-2025-39889","nvd":{"published":"2025-09-24T11:15:32.780","modified":"2026-09-26T00:10:00.127","status":"Modified","description":"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 - 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)","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-326"],"references":["https://git.kernel.org/stable/c/24b2cdfc16e9bd6ab3d03b8e01c590755bd3141f","https://git.kernel.org/stable/c/522e9ed157e3c21b4dd623c79967f72c21e45b78","https://git.kernel.org/stable/c/9e3114958d87ea88383cbbf38c89e04b8ea1bce5","https://git.kernel.org/stable/c/c6d527bbd3d3896375079f5dbc8b7f96734a3ba5","https://git.kernel.org/stable/c/d49798ecd26e0ee7995a7fc1e90ca5cd9b4402d6"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:10:08.713834912+00:00"},"epss":{"cve":"CVE-2025-39889","score":0.00099,"percentile":0.00778,"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."]}