Bluetooth: hci_event: validate skb length for unknown CC opcode
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.159, 6.6.117, 6.12.58, 6.17.8, 6.18
Red Hat 2 advisories
- RHSA-2026:1727 Released 2026-02-02 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.58.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.58.1.el10_0, kernel-64k-devel-6.12.0-55.58.1.el10_0 +12
- Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.58.1.el10_0, kernel-64k-6.12.0-55.58.1.el10_0, kernel-64k-core-6.12.0-55.58.1.el10_0 +28
- Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.58.1.el10_0, libperf-6.12.0-55.58.1.el10_0
- Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.58.1.el10_0, kernel-rt-64k-6.12.0-55.58.1.el10_0, kernel-rt-64k-core-6.12.0-55.58.1.el10_0 +21
- Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.58.1.el10_0, kernel-rt-core-6.12.0-55.58.1.el10_0, kernel-rt-debug-6.12.0-55.58.1.el10_0 +11
- RHSA-2026:1690 Released 2026-02-02 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-124.31.1.el10_1, kernel-64k-debug-devel-matched-6.12.0-124.31.1.el10_1, kernel-64k-devel-6.12.0-124.31.1.el10_1 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-124.31.1.el10_1, kernel-64k-6.12.0-124.31.1.el10_1, kernel-64k-core-6.12.0-124.31.1.el10_1 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-124.31.1.el10_1, libperf-6.12.0-124.31.1.el10_1
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-124.31.1.el10_1, kernel-rt-64k-6.12.0-124.31.1.el10_1, kernel-rt-64k-core-6.12.0-124.31.1.el10_1 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-124.31.1.el10_1, kernel-rt-core-6.12.0-124.31.1.el10_1, kernel-rt-debug-6.12.0-124.31.1.el10_1 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:1690 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:1727 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:1690 |
| Red Hat Enterprise Linux BaseOS EUS (v. 10.0) | Fixed | RHSA-2026:1727 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:1690 |
| Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) | Fixed | RHSA-2026:1727 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:1690 |
| Red Hat Enterprise Linux Real Time EUS (v. 10.0) | Fixed | RHSA-2026:1727 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:1690 |
| Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) | Fixed | RHSA-2026:1727 |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2025-40301
- 2026-10-03 Alias added: GHSA-mp66-rx49-f278
References
Other 5
- https://git.kernel.org/stable/c/fea895de78d3bb2f0c09db9f10b18f8121b15759
- https://git.kernel.org/stable/c/779f83a91d4f1bf5ddfeaf528420cbb6dbf03fa8
- https://git.kernel.org/stable/c/cf2c2acec1cf456c3d11c11a7589e886a0f963a9
- https://git.kernel.org/stable/c/1a0ddaaf97405dbd11d4cb5a961a3f82400e8a50
- https://git.kernel.org/stable/c/5c5f1f64681cc889d9b13e4a61285e9e029d6ab5
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Sources
- CVE-2025-40301 · CVE Program
- CVE-2025-40301 · NVD
- FIRST EPSS
- GHSA-mp66-rx49-f278 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-40301 · Red Hat security data · CC BY 4.0
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