# CVE-2026-64483: ALSA: firewire: isight: bound the sample count to the packet payload

> A malicious FireWire device can trigger a buffer overflow in the Linux kernel ALSA iSight driver, potentially leading to code execution or system crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jul 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-64483, DEBIAN-CVE-2026-64483, GHSA-j22x-mh97-frw2, ROOT-OS-UBUNTU-2204-CVE-2026-64483, UBUNTU-CVE-2026-64483

## What is CVE-2026-64483?

CVE-2026-64483 is a memory corruption vulnerability in Linux, published on 25 Jul 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:

ALSA: firewire: isight: bound the sample count to the packet payload

isight_packet() takes the frame count from the device iso packet and
checks it only against the device claimed iso length.

	count = be32_to_cpu(payload->sample_count);
	if (likely(count <= (length - 16) / 4))
		isight_samples(isight, payload->samples, count);

length is the iso header data_length. It can be up to 0xffff. So the
gate allows a count up to about 16379. isight_samples() then copies
count frames out of payload->samples into the PCM DMA buffer.

payload->samples holds only 2 * MAX_FRAMES_PER_PACKET values. The
device multiplexes two samples per frame. A count past
MAX_FRAMES_PER_PACKET reads past the payload. A count past the buffer
size writes past runtime->dma_area. The smallest PCM buffer is larger
than MAX_FRAMES_PER_PACKET. Bounding the count to MAX_FRAMES_PER_PACKET
keeps both the read and the write in range.

A malicious or faulty Apple iSight on the FireWire bus reaches this
during a normal capture.

Add the MAX_FRAMES_PER_PACKET bound to the gate.

## Which versions are affected by CVE-2026-64483?


## How do I fix CVE-2026-64483?

Apply the vendor's patch.

## Is CVE-2026-64483 being exploited?

There is no known exploitation of CVE-2026-64483 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64483 and fix it if it is affected.

What it is: CVE-2026-64483 is a memory corruption vulnerability in Linux, published on 25 Jul 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-2026-64483 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-2026-64483/ (Markdown: https://insights.sbomify.com/CVE-2026-64483/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64483
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64483
- OSV: https://osv.dev/vulnerability/CVE-2026-64483

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64483/
Summaries are generated and may contain mistakes; the official description above is the record.