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Response snapshot Nov 4, 2026, 06:36 UTC

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VulnerabilityCVE-2026-19935

The Bluetooth LE host queues received L2CAP connection-oriented channel (CoC) data for deferred processing through a struct k_work embedded in the channel object...

The Bluetooth LE host queues received L2CAP connection-oriented channel (CoC) data for deferred processing through a struct k_work embedded in the channel object (le_chan->rx_work, handler l2cap_rx_process()) whenever the channel uses a dynamic PSM (0x0080-0x00FF).

At a glance

Exploited
Not known
Severity
7.5 High (CVSS 3.1)
Chance of exploitation
0.2% in the next 30 days
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-19935 (opens a new tab)

What happened

The Bluetooth LE host queues received L2CAP connection-oriented channel (CoC) data for deferred processing through a struct k_work embedded in the channel object (le_chan->rx_work, handler l2cap_rx_process()) whenever the channel uses a dynamic PSM (0x0080-0x00FF). Channel teardown in l2cap_chan_destroy() in subsys/bluetooth/host/l2cap.

c cancels the retransmission-timeout work and drains the RX FIFO, but never cancels rx_work. Because that work item was submitted to the system workqueue while HCI receive processing runs on the dedicated Bluetooth RX workqueue (CONFIG_BT_RECV_WORKQ_BT, the default), a queued rx_work item can outlive the channel it points into.

A remote, unauthenticated peer with an established CoC channel triggers this by sending a data K-frame immediately followed by an L2CAP Disconnect Request.

The K-frame submits rx_work to the system workqueue; because both workqueue threads are cooperative and the Bluetooth RX workqueue runs at the higher priority (K_PRIO_COOP(CONFIG_BT_RX_PRIO) versus CONFIG_SYSTEM_WORKQUEUE_PRIORITY), the pending item cannot run before the following Disconnect Request is processed in le_disconn_req() -> l2cap_chan_del() -> l2cap_chan_destroy().

Continue reading

The stack then invokes the released() callback, which the API documents as meaning the stack has dropped all references and the application may free the channel memory.

The application therefore frees or re-accepts into an object that the system workqueue still holds in its pending list.

If the memory is freed and reallocated, the workqueue later dereferences a list node and a handler function pointer read from reused memory; if the object is re-used for a later connection, l2cap_chan_add() calls k_work_init() on a still-enqueued work item, corrupting the workqueue's pending list so that unrelated work items are dropped or the queue spins on a looped list.

A related variant lets l2cap_rx_process() run concurrently with teardown, racing the net_buf unref of le_chan->_sdu and the clearing of chan->conn.

The fix routes the channel RX work to the Bluetooth workqueue - the same context in which every teardown path runs - and adds an explicit k_work_cancel() of le_chan->rx_work in l2cap_chan_destroy(), so no reference to the channel survives the released() callback. Configurations without CONFIG_BT_L2CAP_DYNAMIC_CHANNEL, or that only use SIG-assigned PSMs (EATT 0x0027, OTS 0x0025) which take the inline receive path, are not affected.

Scores and how they were measured

CVSS base severity

7.5

Version 3.1As of

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.2%

Scored Percentile 7.5%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Sources

  1. Primary source

    NVD CVE-2026-19935 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  5. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-19935, scored 2026-11-03. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 4). The Bluetooth LE host queues received L2CAP connection-oriented channel (CoC) data for deferred processing through a struct k_work embedded in the channel object... (CVE-2026-19935). https://kevwire.com/record/CVE-2026-19935

MLA

"The Bluetooth LE host queues received L2CAP connection-oriented channel (CoC) data for deferred processing through a struct k_work embedded in the channel object... (CVE-2026-19935)." KEVWire, 4 Nov. 2026, kevwire.com/record/CVE-2026-19935.

Chicago

KEVWire. "The Bluetooth LE host queues received L2CAP connection-oriented channel (CoC) data for deferred processing through a struct k_work embedded in the channel object... (CVE-2026-19935)." Last modified November 4, 2026. https://kevwire.com/record/CVE-2026-19935.

Evidence summary (plain text)

The Bluetooth LE host queues received L2CAP connection-oriented channel (CoC) data for deferred processing through a struct k_work embedded in the channel object... (Oct 11, 2026).
The Bluetooth LE host queues received L2CAP connection-oriented channel (CoC) data for deferred processing through a struct k_work embedded in the channel object (le_chan->rx_work, handler l2cap_rx_process()) whenever the channel uses a dynamic PSM (0x0080-0x00FF). Channel teardown in l2cap_chan_destroy() in subsys/bluetooth/host/l2cap.c cancels the retransmission-timeout work and drains the RX FIFO, but never cancels rx_work.
CVSS 7.5 (version 3.1; evidence as of Nov 4, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-19935).
EPSS 0.2% for the following 30 days, scored Nov 3, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-19935&date=2026-11-03).
Sources:
NVD CVE-2026-19935: https://nvd.nist.gov/vuln/detail/CVE-2026-19935
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-04T05:00:57.032Z&lastModEndDate=2026-11-04T06:35:55.811Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-04T04:31:09.055Z&lastModEndDate=2026-11-04T06:00:55.075Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-04T03:55:55.886Z&lastModEndDate=2026-11-04T05:30:57.785Z&resultsPerPage=500&startIndex=0
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-19935&date=2026-11-03
Record ID: CVE-2026-19935.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 4, 2026, 06:01 UTC. Ingestion is not an independent editorial investigation.

NVD status: Awaiting Analysis. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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