# CVE-2026-53046: ksmbd: fix use-after-free from async crypto on Qualcomm crypto engine

> A use-after-free in the Linux kernel ksmbd module on Qualcomm hardware allows attackers to cause a system crash via async crypto operations.

- **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:** 24 Jun 2026
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2026-53046, DEBIAN-CVE-2026-53046, GHSA-rchw-wq4w-xpmh, ROOT-OS-DEBIAN-12-CVE-2026-53046, ROOT-OS-UBUNTU-2204-CVE-2026-53046, ROOT-OS-UBUNTU-2404-CVE-2026-53046, UBUNTU-CVE-2026-53046

## What is CVE-2026-53046?

CVE-2026-53046 is a critical use after free vulnerability in Linux kernel, published on 24 Jun 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 from async crypto on Qualcomm crypto engine

ksmbd_crypt_message() sets a NULL completion callback on AEAD requests
and does not handle the -EINPROGRESS return code from async hardware
crypto engines like the Qualcomm Crypto Engine (QCE). When QCE returns
-EINPROGRESS, ksmbd treats it as an error and immediately frees the
request while the hardware DMA operation is still in flight. The DMA
completion callback then dereferences freed memory, causing a NULL
pointer crash:

  pc : qce_skcipher_done+0x24/0x174
  lr : vchan_complete+0x230/0x27c
  ...
  el1h_64_irq+0x68/0x6c
  ksmbd_free_work_struct+0x20/0x118 [ksmbd]
  ksmbd_exit_file_cache+0x694/0xa4c [ksmbd]

Use the standard crypto_wait_req() pattern with crypto_req_done() as
the completion callback, matching the approach used by the SMB client
in fs/smb/client/smb2ops.c. This properly handles both synchronous
engines (immediate return) and async engines (-EINPROGRESS followed
by callback notification).

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-53046?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53046?

Apply the vendor's patch.

## Is CVE-2026-53046 being exploited?

There is no known exploitation of CVE-2026-53046 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-2026-53046 and fix it if it is affected.

What it is: CVE-2026-53046 is a critical use after free vulnerability in Linux kernel, published on 24 Jun 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-2026-53046 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-2026-53046/ (Markdown: https://insights.sbomify.com/CVE-2026-53046/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53046
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53046
- OSV: https://osv.dev/vulnerability/CVE-2026-53046

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53046/
Summaries are generated and may contain mistakes; the official description above is the record.