# CVE-2026-68130: ksmbd: defer destroy_previous_session() until after NTLM authentication

> An authenticated attacker can terminate a victim's SMB session by manipulating NTLM authentication fields, causing a 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:** 10 Aug 2026
- **Updated:** 23 Aug 2026
- **Also known as:** BELL-CVE-2026-68130, DEBIAN-CVE-2026-68130, GHSA-cjmw-xwhw-8r5x, UBUNTU-CVE-2026-68130

## What is CVE-2026-68130?

CVE-2026-68130 is a denial of service vulnerability in Linux, published on 10 Aug 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:

ksmbd: defer destroy_previous_session() until after NTLM authentication

In ntlm_authenticate(), destroy_previous_session() is called using a
user pointer resolved from the client-supplied NTLM blob username field
before the NTLMv2 response is validated. An authenticated attacker can
set the NTLM blob username to match a victim account and set
PreviousSessionId to the victim's session ID; destroy_previous_session()
destroys the victim's session while ksmbd_decode_ntlmssp_auth_blob()
subsequently rejects the request with -EPERM.

Move destroy_previous_session() and the prev_id assignment to after
ksmbd_decode_ntlmssp_auth_blob() returns success and use sess->user
rather than the pre-authentication lookup result. This matches the
ordering already used by krb5_authenticate(), where
destroy_previous_session() is called only after
ksmbd_krb5_authenticate() returns success.

## Which versions are affected by CVE-2026-68130?


## How do I fix CVE-2026-68130?

Apply the vendor's patch.

## Is CVE-2026-68130 being exploited?

There is no known exploitation of CVE-2026-68130 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68130 and fix it if it is affected.

What it is: CVE-2026-68130 is a denial of service vulnerability in Linux, published on 10 Aug 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-2026-68130 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-2026-68130/ (Markdown: https://insights.sbomify.com/CVE-2026-68130/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68130
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68130
- OSV: https://osv.dev/vulnerability/CVE-2026-68130

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68130/
Summaries are generated and may contain mistakes; the official description above is the record.