Linux: Improper Locking
CVE-2026-68085 is a high-severity improper locking vulnerability in Linux, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited from the same local network by an attacker with a low-privileged account, without any action from a user. The record lists versions d52446b3e735cfdbdc2a58342163803bc2e64249, b9dd39cf1667e378b25a082ca796d495d578c5d3, 714d861d35d937f23375a4517569b13917bbbe51 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d52446b3e735cfdbdc2a58342163803bc2e64249 or b9dd39cf1667e378b25a082ca796d495d578c5d3 or 714d861d35d937f23375a4517569b13917bbbe51 or 1b0d946d6f08bd39211385bc703a440911b41e46, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 81c7a3c22a0f2808cf4ae0b4908f59763b23606d up to, but not including, d52446b3e735cfdbdc2a58342163803bc2e64249; 192cb0f1ca706d9a1bc36ae0ad5f666d1e4fd894 up to, but not including, b9dd39cf1667e378b25a082ca796d495d578c5d3; c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b up to, but not including, 714d861d35d937f23375a4517569b13917bbbe51; c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b up to, but not including, 1b0d946d6f08bd39211385bc703a440911b41e46; 78aad93e938f013d9272fe0ee168f27883afa95c; e2d19969c8d9198ecc3090bcd5312ecd503a3339; c85cff648a2bc92322912db5f1727ad05afae7b6; 9d20d48be2c4a071fb015eb09bda2cecd25daf34; and 9 more ranges | d52446b3e735cfdbdc2a58342163803bc2e64249, b9dd39cf1667e378b25a082ca796d495d578c5d3, 714d861d35d937f23375a4517569b13917bbbe51, 1b0d946d6f08bd39211385bc703a440911b41e46, 6.12.96, 6.18.39 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_uart: clear HCI_UART_SENDING when write_work is canceled HCI_UART_SENDING bit in tx_state means write_work is pending and blocks queueing it again. Currently this bit is not cleared when canceling the work in hci_uart_close(), which blocks future writes when device is reopened later if write_work was pending. Fix by clearing HCI_UART_SENDING when canceling the work. Also make clearing of tx_skb safe by using disable_work_sync + enable_work instead of just cancel_work_sync. hci_uart_flush() purges the proto tx queue so we can cancel the pending write_work there, instead of doing it just in hci_uart_close(). Re-enable and possibly requeue the work after queue flush.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Locking
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
How developers prevent this class of flaw
- Use industry standard APIs to implement locking mechanism.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Improper Locking vulnerabilities
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Spotted an error? Tell us.