CVE-2026-99091 Bluetooth: MGMT: Fix status of pending commands flushed on power off
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-99091?
CVE-2026-99091 is a vulnerability in Linux, published on 26 Oct 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: MGMT: Fix status of pending commands flushed on power off
cmd_complete_rsp() receives a struct cmd_lookup and, for a pending command that has no cmd_complete callback, falls through to cmd_status_rsp(cmd, data). cmd_status_rsp() reads data as a u8 *, so the status sent comes from the first byte of match->sk's representation, not from match->mgmt_status.
commit f53e1c9c726d ("Bluetooth: MGMT: Fix possible crash on mgmt_index_removed") changed the callers' data from &status to &match and updated the cmd_complete branch to match->mgmt_status, but left the fall-through passing data unchanged.
In mgmt_index_removed() match->sk is NULL, so every such command is answered with status 0x00 (Success) instead of MGMT_STATUS_INVALID_INDEX. In __mgmt_power_off() it is NULL too, unless a Set Powered command was pending: then settings_rsp() has stored that command's socket in match->sk, and the byte sent comes from the socket pointer. Either way the status the caller set, MGMT_STATUS_NOT_POWERED (or MGMT_STATUS_INVALID_INDEX when the device is being unregistered), is lost.
Pass the status the callers set.
This was seen on a QCA9377 laptop: bluetoothd's Start Discovery, pending when the adapter was powered off, was answered with Command Status 0x00 and no parameters, and bluetoothd 5.72 crashed on the zero-length success. BlueZ master has since added the length check on that path ("adapter: Fix crash on short start discovery reply", BlueZ a734b06059cb), but userspace should still be told Not Powered, not Success.
Tested on Ubuntu 7.0.0-31 with a virtual controller (hci_vhci): power off is held in HCI Write Scan Enable while a Start Discovery is submitted, and the flush answers it with status 0x00 before this change and 0x0f (Not Powered) after.
Which versions are affected by CVE-2026-99091?
How do I fix CVE-2026-99091?
Upgrade to a fixed version.
Is CVE-2026-99091 being exploited?
There is no known exploitation of CVE-2026-99091 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-99091, DEBIAN-CVE-2026-99091, GHSA-75m9-vh6c-66mx, UBUNTU-CVE-2026-99091.