---
id: "CVE-2026-98890"
kind: "vulnerability"
aliases: ["CVE-2026-98890"]
title: "Linux kernel: libertas Wi-Fi driver reads past short monitor-mode frames"
severity: "unknown"
cvss: null
epss: 0.00215
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kernel", "libertas", "linux", "wifi"]
not_affected_if: ["module-not-loaded", "no-libertas-hardware"]
published_at: "2026-10-23T12:18:22+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T12:38:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98890", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-98890", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# Linux kernel: libertas Wi-Fi driver reads past short monitor-mode frames

The libertas Wi-Fi driver in the Linux kernel does not check that a monitor-mode transmit frame is long enough before reading its radiotap header and destination address. A short frame can cause the kernel to read memory beyond the end of the packet buffer.

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

## How to check

- Run `uname -r` and compare against the fixed kernel versions in your distribution's advisory
- Check whether the driver is loaded with `lsmod | grep libertas`
- unknown for other checks

## Fix

- Update the Linux kernel to a release that includes the upstream fix 'wifi: libertas: reject short monitor TX frames'
- If the libertas driver is not needed, unload it or blacklist it
- unknown for exact fixed versions

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98890
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-98890

## From the sources

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

wifi: libertas: reject short monitor TX frames

In monitor mode, lbs_hard_start_xmit() casts skb->data to a
radiotap TX header, skips that header, and then copies the 802.11
destination address from offset 4 in the remaining frame.  The
generic length check only rejects zero-length and oversized skbs, so
a short monitor frame can be read past the end of the skb data.

Require enough bytes for the radiotap TX header and the destination
address field before using the monitor-mode header layout.

---

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