CVE Catalog

CVE-2026-93783

Low risk· EPSS 5%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

5th percentile - higher than 5% of all known CVEs

Summary

In Bluetooth RFCOMM, the rfcomm_recv_frame function lacked frame length validation, allowing out-of-bounds reads on truncated frames and length underflow (UINT_MAX) on zero-length frames. The fix rejects frames smaller than the required size.

Risk Assessment

A remote Bluetooth attacker could cause a stack crash, potentially leading to code execution (especially on devices with Bluetooth enabled).

Recommendation

Update the kernel to prevent exploitation via Bluetooth connections.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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).

Vulnerability data from NVD (NIST) · CISA KEV · EPSS