Description
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: validate frame length before control and FCS access

l2cap_data_rcv() unpacks either a two-byte or four-byte control field
without first ensuring that it is present. A short ERTM or streaming-mode
frame can therefore cause an out-of-bounds read.

There is a second short-frame case when CRC16 is enabled. After the
control field is pulled, l2cap_check_fcs() subtracts two from skb->len
without checking it. If fewer than two bytes remain, the subtraction
wraps; skb_trim() leaves the buffer unchanged and the subsequent FCS
load reads past the logical end of the frame.

Validate that the frame contains both its control field and, when
enabled, its FCS before either field is accessed.
Published: 2026-10-18
Score: 6.5 Medium
EPSS: < 1% Very Low
KEV: No
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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Tue, 20 Oct 2026 00:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Sun, 18 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: validate frame length before control and FCS access l2cap_data_rcv() unpacks either a two-byte or four-byte control field without first ensuring that it is present. A short ERTM or streaming-mode frame can therefore cause an out-of-bounds read. There is a second short-frame case when CRC16 is enabled. After the control field is pulled, l2cap_check_fcs() subtracts two from skb->len without checking it. If fewer than two bytes remain, the subtraction wraps; skb_trim() leaves the buffer unchanged and the subsequent FCS load reads past the logical end of the frame. Validate that the frame contains both its control field and, when enabled, its FCS before either field is accessed.
Title Bluetooth: L2CAP: validate frame length before control and FCS access
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T09:19:53.885Z

Reserved: 2026-09-25T10:25:14.350Z

Link: CVE-2026-98457

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:16:56.110

Modified: 2026-10-19T10:18:55.100

Link: CVE-2026-98457

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-18T00:00:00Z

Links: CVE-2026-98457 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-18T23:30:13Z

Weaknesses