# CVE-2026-45811: Apache NimBLE buffer overflow in HCI socket transport

Source: https://junglewise.ai/threats/cve-2026-45811-apache-nimble-buffer-overflow-in-hci-socket-transport  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-24. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-45811 · Severity: info · CVSS 3.1 · Published 2026-07-24

Apache NimBLE is an open-source Bluetooth Low Energy stack. A flaw in how it handles communication with Bluetooth hardware controllers could allow a compromised or malicious controller to crash the system by sending oversized data packets. This issue does not allow for remote attacks over-the-air; it requires physical or local access to the hardware interface.

Technologies: [Apache Software Foundation NimBLE](https://junglewise.ai/threats/technologies/nimble). Vendors: [Apache Software Foundation](https://junglewise.ai/threats/vendors/apache-software-foundation).

## Quick answers

**Is CVE-2026-45811 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45811 being exploited in the wild.

**How severe is CVE-2026-45811?** Informational severity, with a CVSS score of 3.1, published 24 July 2026.

**Which products and versions are affected?** Apache Software Foundation NimBLE through 1.9.0.

**Is there a fix for CVE-2026-45811?** A patch was published on 2026-07-24: Fix committed to mynewt-nimble repository Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45811 attacked?** It is attacked from the adjacent network, in a software library.

**Am I affected by CVE-2026-45811?** Check whether you run Apache Software Foundation NimBLE at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A 'Classic Buffer Overflow' (CWE-120) exists in the HCI socket transport component of Apache NimBLE. The vulnerability is caused by a failure to validate that a received Host Controller Interface (HCI) event fits within the configured event pool before performing a copy operation. An attacker with control over the Bluetooth controller (the hardware/firmware on the other end of the HCI socket) can send an oversized event to trigger the overflow. This cannot be exploited over-the-air via Bluetooth. The issue is fixed in version 1.10.0 by dropping HCI events that exceed the BLE_TRANSPORT_EVT_SIZE configuration.

## Affected products

- Apache Software Foundation Apache NimBLE through 1.9.0

## Timeline

- 2026-07-24: advisory: CVE-2026-45811 published by Apache Software Foundation
- 2026-07-24: patched: Fix committed to mynewt-nimble repository

## References

- [https://github.com/apache/mynewt-nimble/commit/dcc4e4f026109eecd507de9479bb5019306a4a41](https://github.com/apache/mynewt-nimble/commit/dcc4e4f026109eecd507de9479bb5019306a4a41)
- [https://lists.apache.org/thread/5mkz68y1py0o6zmxtc3l1o8grtrb78m0](https://lists.apache.org/thread/5mkz68y1py0o6zmxtc3l1o8grtrb78m0)

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