CVE-2025-40301 Details
Description
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.
A vulnerability exists in the Linux kernel's Bluetooth subsystem, specifically in the handling of command complete events with unknown opcodes. When such an event occurs, the first byte of the remaining data is assumed to contain the return status. However, the parameter data may have been cleared by a previous function, potentially leaving the data buffer empty. This can result in reading uninitialized memory, leading to undefined behavior. The issue has been addressed by adding a check for the data length before accessing the return status byte.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for downloading the patched version are available on the official Linux kernel website.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Dec 8, 2025References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/1a0ddaaf97405dbd11d4cb5a961a3f82400e8a50 | kernel.org | Source CodeVendor |
| https://git.kernel.org/stable/c/5c5f1f64681cc889d9b13e4a61285e9e029d6ab5 | kernel.org | Source CodeVendor |
| https://git.kernel.org/stable/c/779f83a91d4f1bf5ddfeaf528420cbb6dbf03fa8 | kernel.org | Source CodeVendor |
| https://git.kernel.org/stable/c/cf2c2acec1cf456c3d11c11a7589e886a0f963a9 | kernel.org | Source CodeVendor |
| https://git.kernel.org/stable/c/fea895de78d3bb2f0c09db9f10b18f8121b15759 | kernel.org | Source CodeVendor |
Weakness Enumeration
No weakness enumeration is available for this CVE.
Affected Products
| Product | Versions |
|---|---|
| Linux kernel | All versions |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 30, 2026 | CVE Modified | kernel.org |
| Jun 17, 2026 | CVE Modified | kernel.org |
| Dec 8, 2025 | New CVE Received | kernel.org |