# CVE-2026-90152: smb/server: fix session leak in ksmbd_session_register()

> A session leak in the Linux kernel's ksmbd SMB server allows authenticated users to exhaust resources, causing denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-102975, BELL-CVE-2026-90152, DEBIAN-CVE-2026-90152, GHSA-c2gf-579m-pqr2, UBUNTU-CVE-2026-90152

## What is CVE-2026-90152?

CVE-2026-90152 is a denial of service vulnerability in Linux, published on 17 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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

smb/server: fix session leak in ksmbd_session_register()

See the procedure below:

  smb2_sess_setup
    ksmbd_smb2_session_create
      __session_create
        atomic_set(&sess->refcnt, 2)
        hash_add(sessions_table, &sess->hlist, sess->id)
    ksmbd_session_register
      xa_store(&conn->sessions, sess->id, sess) // fail
    ksmbd_user_session_put
      atomic_dec(&sess->refcnt) // refcnt is 1, session is not freed

Remove the session from sessions_table and drop its table reference if
xa_store() fails.

## Which versions are affected by CVE-2026-90152?


## How do I fix CVE-2026-90152?

Apply the vendor's patch.

## Is CVE-2026-90152 being exploited?

There is no known exploitation of CVE-2026-90152 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90152 and fix it if it is affected.

What it is: CVE-2026-90152 is a denial of service vulnerability in Linux, published on 17 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90152 in the wild and no public exploit code.

Affected product: 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-2026-90152/ (Markdown: https://insights.sbomify.com/CVE-2026-90152/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90152
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90152
- OSV: https://osv.dev/vulnerability/CVE-2026-90152

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90152/
Summaries are generated and may contain mistakes; the official description above is the record.