# CVE-2025-37778: ksmbd: Fix dangling pointer in krb_authenticate

> A use-after-free vulnerability in the Linux kernel's ksmbd module allows attackers to execute arbitrary code or escalate privileges via crafted SMB2 session setup requests.

- **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:** 1 May 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2025-37778, DEBIAN-CVE-2025-37778, GHSA-45gw-fx24-h4pv, ROOT-OS-DEBIAN-12-CVE-2025-37778, ROOT-OS-UBUNTU-2204-CVE-2025-37778, ROOT-OS-UBUNTU-2404-CVE-2025-37778, UBUNTU-CVE-2025-37778

## What is CVE-2025-37778?

CVE-2025-37778 is a critical use after free vulnerability in Debian Debian Linux, published on 1 May 2025. 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 dangling pointer in krb_authenticate

krb_authenticate frees sess->user and does not set the pointer
to NULL. It calls ksmbd_krb5_authenticate to reinitialise
sess->user but that function may return without doing so. If
that happens then smb2_sess_setup, which calls krb_authenticate,
will be accessing free'd memory when it later uses sess->user.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-37778?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-37778?

Apply the vendor's patch.

## Is CVE-2025-37778 being exploited?

There is no known exploitation of CVE-2025-37778 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-37778 and fix it if it is affected.

What it is: CVE-2025-37778 is a critical use after free vulnerability in Debian Debian Linux, published on 1 May 2025. 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-2025-37778 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2025-37778/ (Markdown: https://insights.sbomify.com/CVE-2025-37778/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37778
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37778
- OSV: https://osv.dev/vulnerability/CVE-2025-37778

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37778/
Summaries are generated and may contain mistakes; the official description above is the record.