---
id: "CVE-2026-98458"
kind: "vulnerability"
aliases: ["CVE-2026-98458"]
title: "Linux kernel: Bluetooth CIS connection leaks an unused reference hold"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["bluetooth", "linux-kernel", "runtime", "self-hosted"]
not_affected_if: ["bluetooth-disabled", "no-bluetooth-iso"]
published_at: "2026-10-18T16:16:56+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:27:17+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98458", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel: Bluetooth CIS connection leaks an unused reference hold

The Linux kernel's Bluetooth ISO layer keeps an extra connection reference when a socket re-requests a CIS it already holds, or when another socket tries to reuse one, so the reference is never released. The sources describe a resource leak and do not state an attacker-controlled impact.

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

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98458

## From the sources

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

Bluetooth: ISO: release unused CIS holds after channel attach

hci_bind_cis() and hci_connect_cis() return one hci_conn hold for the
ISO layer.  A new channel association consumes that hold, which is
eventually released by iso_conn_free().

There are two cases where iso_chan_add() does not create an association:
it returns success when the socket is already attached to the same
iso_conn, and it returns -EBUSY when another socket is attached.  The
hold returned for the current call is unused in both cases.  This occurs
when deferred setup calls iso_connect_cis() again for its existing
socket, or when another socket attempts to reuse the CIS.

Detect the idempotent case while the connection is locked and release
the unused hold after iso_chan_add().  Also release it on -EBUSY.  Do not
drop it for other errors: a newly allocated iso_conn releases the
transferred hold when its last temporary reference is put.

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