# CVE-2025-68817: ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency

> A use-after-free vulnerability in the Linux kernel's ksmbd module allows attackers to potentially execute code or escalate privileges under high concurrency.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Jan 2026
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-68817, DEBIAN-CVE-2025-68817, GHSA-77h3-779x-v4x3, ROOT-OS-DEBIAN-12-CVE-2025-68817, ROOT-OS-DEBIAN-13-CVE-2025-68817, ROOT-OS-UBUNTU-2204-CVE-2025-68817, ROOT-OS-UBUNTU-2404-CVE-2025-68817, UBUNTU-CVE-2025-68817

## What is CVE-2025-68817?

CVE-2025-68817 is a critical use after free vulnerability in Linux kernel, published on 13 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency

Under high concurrency, A tree-connection object (tcon) is freed on
a disconnect path while another path still holds a reference and later
executes *_put()/write on it.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-68817?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-68817?

Apply the vendor's patch.

## Is CVE-2025-68817 being exploited?

There is no known exploitation of CVE-2025-68817 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68817 and fix it if it is affected.

What it is: CVE-2025-68817 is a critical use after free vulnerability in Linux kernel, published on 13 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-68817 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-68817/ (Markdown: https://insights.sbomify.com/CVE-2025-68817/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68817
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68817
- OSV: https://osv.dev/vulnerability/CVE-2025-68817

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68817/
Summaries are generated and may contain mistakes; the official description above is the record.