{"id":"CVE-2026-93783","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: validate skb length in rfcomm_recv_frame\n\nrfcomm_recv_frame() casts skb->data to struct rfcomm_hdr and dereferences\nhdr->addr and hdr->ctrl without v…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: validate skb length in rfcomm_recv_frame\n\nrfcomm_recv_frame() casts skb->data to struct rfcomm_hdr and dereferences\nhdr->addr and hdr->ctrl without v…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 67dc3b40fae71b6b11c71e7ff69bac0758818c05","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < b230e5bf501c5edaf2eb0991cb862ac142031d4b","Linux < 6.12.111","Linux < 6.18.53","Linux (all versions)"],"published":"2026-09-24","updated":"2026-09-24","sourceUpdated":"2026-09-24T17:17:10.907","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93783","references":[{"url":"https://git.kernel.org/stable/c/67dc3b40fae71b6b11c71e7ff69bac0758818c05","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b230e5bf501c5edaf2eb0991cb862ac142031d4b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-24T16:47:15.904Z","slug":"CVE-2026-93783","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: validate skb length in rfcomm_recv_frame\n\nrfcomm_recv_frame() casts skb->data to struct rfcomm_hdr and dereferences\nhdr->addr and hdr->ctrl without validating skb->len first. A truncated\nframe with skb->len less than the minimum header size causes an\nout-of-bounds read of uninitialized memory. Additionally, a zero-length\nframe causes skb->len-- to underflow to UINT_MAX, making\nskb_tail_pointer() read far past the buffer.\n\nCommit 23882b828c3c (\"Bluetooth: RFCOMM: validate skb length in MCC\nhandlers\") fixed the same class of missing-length-check bugs in the MCC\nsub-handlers, but the top-level rfcomm_recv_frame() was left unfixed.\nKMSAN reports:\n\n  BUG: KMSAN: uninit-value in rfcomm_run\n  ...\n  Uninit was created at:\n    __alloc_skb+0x474/0xb60\n    vhci_write+0xe9/0x870\n\nFix this by rejecting frames smaller than sizeof(struct rfcomm_hdr) + 1\n(the minimum frame must have a 3-byte header and a 1-byte FCS).\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":[]}