# CVE-2026-72492: ksmbd: fix use-after-free in same_client_has_lease()

> A use-after-free in the Linux kernel's ksmbd module allows attackers to potentially execute code or escalate privileges via concurrent lease operations.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-72492, DEBIAN-CVE-2026-72492, GHSA-h9qg-8gf5-6w98, UBUNTU-CVE-2026-72492

## What is CVE-2026-72492?

CVE-2026-72492 is a high-severity use after free vulnerability in Linux, published on 15 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: fix use-after-free in same_client_has_lease()

same_client_has_lease() returns an opinfo pointer from ci->m_op_list
after dropping ci->m_lock without taking a reference.

smb_grant_oplock() then dereferences that pointer in copy_lease() and
when checking breaking_cnt. A concurrent close can remove the old lease
from ci->m_op_list and drop the last reference before the caller uses
the returned pointer, leading to a use-after-free.

Take a reference when same_client_has_lease() selects an existing lease,
drop any previous match while scanning, and release the returned
reference in smb_grant_oplock() after copying the lease state.

## Which versions are affected by CVE-2026-72492?


## How do I fix CVE-2026-72492?

Apply the vendor's patch.

## Is CVE-2026-72492 being exploited?

There is no known exploitation of CVE-2026-72492 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72492 and fix it if it is affected.

What it is: CVE-2026-72492 is a high-severity use after free vulnerability in Linux, published on 15 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-2026-72492 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-2026-72492/ (Markdown: https://insights.sbomify.com/CVE-2026-72492/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72492
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72492
- OSV: https://osv.dev/vulnerability/CVE-2026-72492

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72492/
Summaries are generated and may contain mistakes; the official description above is the record.