CVE-2026-64206 Linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for pending_rx_work. process_pending_rx() takes the same mutex, so teardown can deadlock against the worker it is flushing. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the l2cap_conn_ready() -> queue_work(..., &conn->pending_rx_work) submit path, the l2cap_conn_del() -> cancel_work_sync(&conn->pending_rx_work) teardown path, and the process_pending_rx() -> mutex_lock(&conn->lock) worker edge. Lockdep WARNING: possible circular locking dependency detected process_pending_rx+0x21/0x2a [vuln_msv] l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv] *** DEADLOCK *** Cancel pending_rx_work before taking conn->lock, matching the existing lock-before-drain ordering used for the two delayed works in the same teardown path. The pending_rx queue is still purged after the work has been cancelled and conn->lock has been acquired.
Browse Linux security risksQuick answer
Linux should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- < d5616beb3355b5fca2280d796c1cf7ada4ee6551
- < e96fbac8d3a73b0bc165383c092a30628561d320
- < 2641a9e0a1dd4af2e21995470a21d55dd35e5203
- ee805f9499ebd0edf0877990968543c752043b59
- < 3.16
- 3.16
Fixed versions
- 6.18.39
- 7.1.4
- 7.2-rc3
How to fix it
CVE-2026-64206 affects Linux and involves security-control failure. Successful exploitation may affect the confidentiality, integrity, or availability of the affected workflow. Prioritize deployments that process untrusted input, expose the affected feature, or hold sensitive data. Upgrade Linux to 6.18.39, 7.1.4, 7.2-rc3 or a later vendor-supported fixed release.
- Inventory every deployment, device, package, plugin, container, build, and environment that uses Linux.
- Compare the installed version with the recorded affected range: < d5616beb3355b5fca2280d796c1cf7ada4ee6551, < e96fbac8d3a73b0bc165383c092a30628561d320, < 2641a9e0a1dd4af2e21995470a21d55dd35e5203, ee805f9499ebd0edf0877990968543c752043b59, < 3.16, 3.16.
- Upgrade Linux to 6.18.39, 7.1.4, 7.2-rc3 or a later vendor-supported fixed release.
- Until patched, reduce public exposure, disable the affected workflow where practical, and allow access only from trusted users and systems.
- Review configuration, roles, tokens, network paths, and exposed endpoints connected to Linux; remove access that is not required.
- Review application, system, proxy, and audit logs for requests and behavior linked to the affected feature and CVE.
- If exploitation is suspected, isolate affected assets, preserve evidence, rotate exposed credentials or keys, restore trusted data, and rebuild compromised systems before returning them to service.
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Verify the fix
- Confirm every affected asset now runs the fixed vendor-supported release or has the documented mitigation for CVE-2026-64206 in place.
- Use a safe regression test to confirm the affected security-control failure path no longer produces the vulnerable behavior.
- Confirm temporary access controls, endpoint restrictions, network blocks, and least-privilege settings remain effective after the update.
- Review post-remediation logs and rerun Fixnx plus the relevant package, dependency, firmware, browser, or product-specific security check.
- Document affected assets, versions, changes, validation evidence, reviewed logs, and any credential rotation, cleanup, or replacement completed.
Related categories
Related security risks
More published guidance from the same primary category.
Trusted references
FAQ
What is affected by CVE-2026-64206?
Linux versions listed as affected should be reviewed: < d5616beb3355b5fca2280d796c1cf7ada4ee6551, < e96fbac8d3a73b0bc165383c092a30628561d320, < 2641a9e0a1dd4af2e21995470a21d55dd35e5203, ee805f9499ebd0edf0877990968543c752043b59, < 3.16, 3.16.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.