{"cve":"CVE-2026-46186","nvd":{"published":"2026-05-28T10:16:34.223","modified":"2026-06-17T10:53:14.353","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: virtio_bt: validate rx pkt_type header length\n\nvirtbt_rx_handle() reads the leading pkt_type byte from the RX skb\nand forwards the remainder to hci_recv_frame() for every\nevent/ACL/SCO/ISO type, without checking that the remaining payload\nis at least the fixed HCI header for that type.\n\nAfter the preceding patch bounds the backend-supplied used.len to\n[1, VIRTBT_RX_BUF_SIZE], a one-byte completion still reaches\nhci_recv_frame() with skb->len already pulled to 0. If the byte\nhappened to be HCI_ACLDATA_PKT, the ACL-vs-ISO classification\nfast-path in hci_dev_classify_pkt_type() dereferences\nhci_acl_hdr(skb)->handle whenever the HCI device has an active\nCIS_LINK, BIS_LINK, or PA_LINK connection, reading two bytes of\nuninitialized RX-buffer data. The same hazard exists for every\npacket type the driver accepts because none of the switch cases in\nvirtbt_rx_handle() check skb->len against the per-type minimum HCI\nheader size before handing the frame to the core.\n\nAfter stripping pkt_type, require skb->len to cover the fixed\nheader size for the selected type (event 2, ACL 4, SCO 3, ISO 4)\nbefore calling hci_recv_frame(); drop ratelimited otherwise.\nUnknown pkt_type values still take the original kfree_skb() default\npath.\n\nUse bt_dev_err_ratelimited() because both the length and pkt_type\nvalues come from an untrusted backend that can otherwise flood the\nkernel log.","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-908"],"references":["https://git.kernel.org/stable/c/149cfb42ad69c7964fd9f2c43831da9152007129","https://git.kernel.org/stable/c/1e1e509b6fd2a42421745bbcd98bd16daad20904","https://git.kernel.org/stable/c/2c1143564c71e7497b42d8360a8379ccbb011d3c","https://git.kernel.org/stable/c/3485c7236c59c8c34a41af1c4b52982437554e79","https://git.kernel.org/stable/c/7b2d4c04816cdc887f472caaf7fc966cfc107e40"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:36:28.938604137+00:00"},"epss":{"cve":"CVE-2026-46186","score":0.00123,"percentile":0.01998,"date":"2026-11-01"},"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."]}