CVE-2026-98600
Received
Received - Intake
Bluetooth Frame Length Validation Flaw in Linux Kernel
Vulnerability report for CVE-2026-98600, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-18
Last updated on: 2026-10-18
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()
While rfcomm_recv_frame() verifies that skb->len is at least
sizeof(*hdr) + 1 (4 bytes: 3-byte header + 1-byte FCS), an RFCOMM frame
with an extended 2-byte length field (!__test_ea(hdr->len)) has a 4-byte
header plus a 1-byte FCS (5 bytes minimum, sizeof(*hdr) + 2).
When a 4-byte RFCOMM frame with EA == 0 arrives:
1. The initial skb->len < sizeof(*hdr) + 1 check passes (4 < 4 is false).
2. Trimming the FCS byte decrements skb->len to 3.
3. If __check_fcs() succeeds, skb_pull(skb, 4) fails (4 > 3) and returns
NULL without advancing skb->data.
4. Because the return value of skb_pull() is ignored, the un-pulled
3-byte struct rfcomm_hdr remains at skb->data and is either queued as
application payload via rfcomm_recv_data() or parsed as a multiplexer
control command via rfcomm_recv_mcc() on DLCI 0.
Fix this by extending the length check in rfcomm_recv_frame() to also
require skb->len >= sizeof(*hdr) + 2 when !__test_ea(hdr->len).
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | fb40eda15122f6b780228639c1ead6820340ff54 |
| Linux | Linux | 3829af5fab5a22405bf1e7d69068c2ec0fce46ca |
| Linux | Linux | b161eacd7fa4a2d765724b5504ac6cc388e48f80 |
| Linux | Linux | 30d1d9f3495463f7c026e4c553127f79b486fcd6 |
| Linux | Linux | 67dc3b40fae71b6b11c71e7ff69bac0758818c05 |
| Linux | Linux | bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51 |
| Linux | Linux | b230e5bf501c5edaf2eb0991cb862ac142031d4b |
| Linux | Linux | b230e5bf501c5edaf2eb0991cb862ac142031d4b |
| Linux | Linux | 6.12.111 |
| Linux | Linux | 6.18.53 |
| Linux | Linux | 7.2 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
