# CVE-2026-99003: drm/panthor: validate userspace queue count against initialized firmware slot count


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** BELL-CVE-2026-99003, DEBIAN-CVE-2026-99003, GHSA-chr3-6fxw-gjw4, UBUNTU-CVE-2026-99003

## What is CVE-2026-99003?

CVE-2026-99003 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

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

drm/panthor: validate userspace queue count against initialized firmware slot count

In panthor_drv.c:panthor_ioctl_group_create(),
the queue count is validated against the hardcoded maximum:

	if (!args->queues.count || args->queues.count > MAX_CS_PER_CSG)
		return -EINVAL;

However, if the firmware reports fewer slots than MAX_CS_PER_CSG,
panthor_fw_init_ifaces() will only initialize that smaller number of
stream interfaces.

If unprivileged userspace requests more queues than the firmware reported
(but no more than MAX_CS_PER_CSG), cs_slot_prog_locked() fetches an
uninitialized stream interface and may crash when dereferencing
cs_iface->input->ringbuf_base.

## Which versions are affected by CVE-2026-99003?


## How do I fix CVE-2026-99003?

Upgrade to a fixed version.

## Is CVE-2026-99003 being exploited?

There is no known exploitation of CVE-2026-99003 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99003 and fix it if it is affected.

What it is: CVE-2026-99003 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99003 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-2026-99003/ (Markdown: https://insights.sbomify.com/CVE-2026-99003/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99003
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99003
- OSV: https://osv.dev/vulnerability/CVE-2026-99003

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99003/
Summaries are generated and may contain mistakes; the official description above is the record.