CVE-2026-93783: Linux

EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: validate skb length in rfcomm_recv_frame rfcomm_recv_frame() casts skb->data to struct rfcomm_hdr and dereferences hdr->addr and hdr->ctrl without validating skb->len first. A truncated frame with skb->len less than the minimum header size causes an out-of-bounds read of uninitialized memory. Additionally, a zero-length frame causes skb->len-- to underflow to UINT_MAX, making skb_tail_pointer() read far past the buffer. Commit 23882b828c3c ("Bluetooth: RFCOMM: validate skb length in MCC handlers") fixed the same class of missing-length-check bugs in the MCC sub-handlers, but the top-level rfcomm_recv_frame() was left unfixed. KMSAN reports: BUG: KMSAN: uninit-value in rfcomm_run ... Uninit was created at: __alloc_skb+0x474/0xb60 vhci_write+0xe9/0x870 Fix this by rejecting frames smaller than sizeof(struct rfcomm_hdr) + 1 (the minimum frame must have a 3-byte header and a 1-byte FCS).

Affected products

• Linux Linux: from 2.6.12, before 5.10.271 (fixed in 5.10.271); from 5.11, before 5.15.222 (fixed in 5.15.222); from 5.16, before 6.1.189 (fixed in 6.1.189); from 6.2, before 6.6.158 (fixed in 6.6.158); from 6.7, before 6.12.111 (fixed in 6.12.111); from 6.13, before 6.18.53 (fixed in 6.18.53); …

Published 2026-09-24. Last modified 2026-10-03.