Review reviewHigh

CVE-2025-40301

Linux

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: validate skb length for unknown CC opcode In hci_cmd_complete_evt(), if the command complete event has an unknown opcode, we assume the first byte of the remaining skb->data contains the return status. However, parameter data has previously been pulled in hci_event_func(), which may leave the skb empty. If so, using skb->data[0] for the return status uses un-init memory. The fix is to check skb->len before using skb->data.

CVSS: 7.6
EPSS: 0.27%
CISA KEV: Not listed
Published: 2025.12.08

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.27%

Technical severityCVSS 7.6

Vulnerability overview

Affected product and versions

Product: Linux
Affected versions: >= afcb3369f46ed5dc883a7b92f2dd1e264d79d388 < fea895de78d3bb2f0c09db9f10b18f8121b15759, >= afcb3369f46ed5dc883a7b92f2dd1e264d79d388 < 779f83a91d4f1bf5ddfeaf528420cbb6dbf03fa8, >= afcb3369f46ed5dc883a7b92f2dd1e264d79d388 < cf2c2acec1cf456c3d11c11a7589e886a0f963a9, >= afcb3369f46ed5dc883a7b92f2dd1e264d79d388 < 1a0ddaaf97405dbd11d4cb5a961a3f82400e8a50, >= afcb3369f46ed5dc883a7b92f2dd1e264d79d388 < 5c5f1f64681cc889d9b13e4a61285e9e029d6ab5, >= 6.1
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Linux and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
CWE: Not available