# CVE-2026-43156: net: usb: pegasus: enable basic endpoint checking

> A malicious USB device can cause a denial of service in the Linux kernel pegasus driver by presenting mismatched endpoint descriptors.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 May 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-43156, DEBIAN-CVE-2026-43156, GHSA-4pc7-q2m2-j888, ROOT-OS-DEBIAN-11-CVE-2026-43156, ROOT-OS-UBUNTU-2204-CVE-2026-43156, ROOT-OS-UBUNTU-2404-CVE-2026-43156, UBUNTU-CVE-2026-43156

## What is CVE-2026-43156?

CVE-2026-43156 is a medium-severity denial of service vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

net: usb: pegasus: enable basic endpoint checking

pegasus_probe() fills URBs with hardcoded endpoint pipes without
verifying the endpoint descriptors:

  - usb_rcvbulkpipe(dev, 1) for RX data
  - usb_sndbulkpipe(dev, 2) for TX data
  - usb_rcvintpipe(dev, 3)  for status interrupts

A malformed USB device can present these endpoints with transfer types
that differ from what the driver assumes.

Add a pegasus_usb_ep enum for endpoint numbers, replacing magic
constants throughout. Add usb_check_bulk_endpoints() and
usb_check_int_endpoints() calls before any resource allocation to
verify endpoint types before use, rejecting devices with mismatched
descriptors at probe time, and avoid triggering assertion.

Similar fix to
- commit 90b7f2961798 ("net: usb: rtl8150: enable basic endpoint checking")
- commit 9e7021d2aeae ("net: usb: catc: enable basic endpoint checking")

## Which versions are affected by CVE-2026-43156?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43156?

Apply the vendor's patch.

## Is CVE-2026-43156 being exploited?

There is no known exploitation of CVE-2026-43156 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43156 and fix it if it is affected.

What it is: CVE-2026-43156 is a medium-severity denial of service vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-43156 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-43156/ (Markdown: https://insights.sbomify.com/CVE-2026-43156/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43156
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43156
- OSV: https://osv.dev/vulnerability/CVE-2026-43156

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43156/
Summaries are generated and may contain mistakes; the official description above is the record.