# CVE-2026-89441: mmc: via-sdmmc: cancel card-detect work on remove

> A use-after-free vulnerability in the Linux kernel's via-sdmmc driver allows attackers to cause memory corruption or system crashes by triggering card detection during device removal.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-100761, BELL-CVE-2026-89441, DEBIAN-CVE-2026-89441, GHSA-6v98-4pph-jq73, UBUNTU-CVE-2026-89441

## What is CVE-2026-89441?

CVE-2026-89441 is a high-severity use after free vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

mmc: via-sdmmc: cancel card-detect work on remove

Disabling the device interrupt and freeing the IRQ prevents new card-detect
work from being queued, but carddet_work already queued by the handler can
still run after via_sd_remove() returns. via_sdc_card_detect() recovers the
host through container_of() and dereferences its MMIO base; once remove()
returns the host can be freed, so that work would touch freed memory.

Cancel carddet_work after freeing the IRQ and before cancelling
finish_bh_work, which the card-detect handler can also queue. carddet_work
can re-enable the interrupt through via_reset_pcictrl(); mask it again
afterwards.

This issue was found by an in-house static analysis tool and confirmed by
manual code review.

## Which versions are affected by CVE-2026-89441?


## How do I fix CVE-2026-89441?

Apply the vendor's patch.

## Is CVE-2026-89441 being exploited?

There is no known exploitation of CVE-2026-89441 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89441 and fix it if it is affected.

What it is: CVE-2026-89441 is a high-severity use after free vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-89441 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-2026-89441/ (Markdown: https://insights.sbomify.com/CVE-2026-89441/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89441
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89441
- OSV: https://osv.dev/vulnerability/CVE-2026-89441

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89441/
Summaries are generated and may contain mistakes; the official description above is the record.