# CVE-2026-68184: cdrom: fix stack out-of-bounds read in CDROMVOLCTRL

> A local attacker with access to CD-ROM devices can trigger a stack out-of-bounds read in the Linux kernel, potentially leaking memory or causing a crash.

- **Severity:** Not scored
- **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:** 10 Aug 2026
- **Updated:** 19 Aug 2026
- **Also known as:** BELL-CVE-2026-68184, DEBIAN-CVE-2026-68184, GHSA-j56f-w52c-9vh2, UBUNTU-CVE-2026-68184

## What is CVE-2026-68184?

CVE-2026-68184 is a memory corruption vulnerability in Linux, published on 10 Aug 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:

cdrom: fix stack out-of-bounds read in CDROMVOLCTRL

mmc_ioctl_cdrom_volume() first reads the audio control mode page into a
32-byte stack buffer with cgc->buflen set to 24.  If the device reports a
block descriptor, the function increases cgc->buflen to include that
descriptor and reads the page again.

For CDROMVOLCTRL, the function then builds a MODE SELECT parameter list
by moving cgc->buffer forward by offset - 8 bytes.  This drops the block
descriptor from the outgoing payload and leaves a new 8-byte mode
parameter header in front of the audio control page.  However, cgc->buflen
is left unchanged.

With a standard 8-byte block descriptor, cgc->buffer points at buffer + 8
but cgc->buflen remains 32.  cdrom_mode_select() therefore asks the low
level packet path to write 32 bytes from that adjusted pointer, reading 8
bytes past the end of the 32-byte stack buffer.

This is not hit by CDROMVOLREAD, and CDROMVOLCTRL only triggers it on
drives that return a non-zero block descriptor length, which helps explain
why it has gone unnoticed.  The overread is also sent to the device as
extra MODE SELECT payload, so it may not produce an obvious local failure.

Reduce cgc->buflen by the same amount as the buffer pointer adjustment so
the MODE SELECT transfer covers only the intended parameter list.

## Which versions are affected by CVE-2026-68184?


## How do I fix CVE-2026-68184?

Apply the vendor's patch.

## Is CVE-2026-68184 being exploited?

There is no known exploitation of CVE-2026-68184 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68184 and fix it if it is affected.

What it is: CVE-2026-68184 is a memory corruption vulnerability in Linux, published on 10 Aug 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-2026-68184 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-2026-68184/ (Markdown: https://insights.sbomify.com/CVE-2026-68184/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68184
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68184
- OSV: https://osv.dev/vulnerability/CVE-2026-68184

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68184/
Summaries are generated and may contain mistakes; the official description above is the record.