---
id: "CVE-2026-98459"
kind: "vulnerability"
aliases: ["CVE-2026-98459"]
title: "Linux kernel Bluetooth ISO: parent connection can be dropped while in use"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["bluetooth", "linux-kernel", "other"]
not_affected_if: ["no-bluetooth-iso"]
published_at: "2026-10-18T16:16:56+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:27:15+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98459", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel Bluetooth ISO: parent connection can be dropped while in use

In the Linux kernel's Bluetooth ISO code, adding a BIS link does not take its own hold on the parent connection, so unlinking a child can drop the parent's hold and schedule it for disconnection while a socket still uses it. The sources do not state what an attacker can do beyond this use-after-release style disruption.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- Apply the upstream Linux kernel fix that takes a hold on the parent in hci_bind_bis(), referenced in the NVD entry for CVE-2026-98459.

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98459

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: ISO: balance the parent hold in hci_bind_bis()

hci_conn_link() takes a lifetime reference to its parent with
hci_conn_get(), but only takes an operational hold on the child.
hci_conn_unlink() later balances both a hold and a reference on the
parent.

The SCO and CIS paths pass a parent acquired from a connect helper, so
it already has a hold. For an additional BIS, hci_bind_bis() obtains the
parent from hci_conn_hash_lookup_big(), which returns a bare pointer.
Unlinking the child then drops the parent's existing hold and can
schedule it for disconnection while its socket is still using it.

Take a hold on the parent before linking it and drop that hold if linking
fails. A successful link transfers the hold to hci_conn_unlink().

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_