{"cve":"CVE-2026-31773","nvd":{"published":"2026-05-01T15:16:40.587","modified":"2026-10-19T20:17:58.853","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: SMP: derive legacy responder STK authentication from MITM state\n\nThe legacy responder path in smp_random() currently labels the stored\nSTK as authenticated whenever pending_sec_level is BT_SECURITY_HIGH.\nThat reflects what the local service requested, not what the pairing\nflow actually achieved.\n\nFor Just Works/Confirm legacy pairing, SMP_FLAG_MITM_AUTH stays clear\nand the resulting STK should remain unauthenticated even if the local\nside requested HIGH security. Use the established MITM state when\nstoring the responder STK so the key metadata matches the pairing result.\n\nThis also keeps the legacy path aligned with the Secure Connections code,\nwhich already treats JUST_WORKS/JUST_CFM as unauthenticated.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-287"],"references":["https://git.kernel.org/stable/c/061ee71ac6b03c9f8432fe49538c3682bfcf4cf3","https://git.kernel.org/stable/c/0afc846bd80073ffcd2b8040f2b2fafaea3d9f72","https://git.kernel.org/stable/c/20756fec2f0108cb88e815941f1ffff88dc286fe","https://git.kernel.org/stable/c/667f44f1392df6482483756458c48670e579e9ff","https://git.kernel.org/stable/c/929db734d12db41ca5f95424db4612397f1bd4a7"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-31773","score":0.00279,"percentile":0.20179,"date":"2026-10-25"},"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."]}