# CVE-2025-38198: fbcon: Make sure modelist not set on unregistered console

> A local attacker can trigger a kernel crash by writing to a sysfs node when a console is unregistered, causing a denial of service.

- **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:** 4 Jul 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-64662, AZL-72769, BELL-CVE-2025-38198, DEBIAN-CVE-2025-38198, GHSA-2v92-8hh5-248m, ROOT-OS-DEBIAN-11-CVE-2025-38198, ROOT-OS-DEBIAN-12-CVE-2025-38198, ROOT-OS-UBUNTU-2204-CVE-2025-38198, ROOT-OS-UBUNTU-2404-CVE-2025-38198, UBUNTU-CVE-2025-38198

## What is CVE-2025-38198?

CVE-2025-38198 is a high-severity vulnerability in Debian Debian Linux, published on 4 Jul 2025. 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:

fbcon: Make sure modelist not set on unregistered console

It looks like attempting to write to the "store_modes" sysfs node will
run afoul of unregistered consoles:

UBSAN: array-index-out-of-bounds in drivers/video/fbdev/core/fbcon.c:122:28
index -1 is out of range for type 'fb_info *[32]'
...
 fbcon_info_from_console+0x192/0x1a0 drivers/video/fbdev/core/fbcon.c:122
 fbcon_new_modelist+0xbf/0x2d0 drivers/video/fbdev/core/fbcon.c:3048
 fb_new_modelist+0x328/0x440 drivers/video/fbdev/core/fbmem.c:673
 store_modes+0x1c9/0x3e0 drivers/video/fbdev/core/fbsysfs.c:113
 dev_attr_store+0x55/0x80 drivers/base/core.c:2439

static struct fb_info *fbcon_registered_fb[FB_MAX];
...
static signed char con2fb_map[MAX_NR_CONSOLES];
...
static struct fb_info *fbcon_info_from_console(int console)
...
        return fbcon_registered_fb[con2fb_map[console]];

If con2fb_map contains a -1 things go wrong here. Instead, return NULL,
as callers of fbcon_info_from_console() are trying to compare against
existing "info" pointers, so error handling should kick in correctly.

Weakness: CWE-129 (Improper Validation of Array Index)

## Which versions are affected by CVE-2025-38198?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-38198?

Apply the vendor's patch.

## Is CVE-2025-38198 being exploited?

There is no known exploitation of CVE-2025-38198 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-38198 and fix it if it is affected.

What it is: CVE-2025-38198 is a high-severity vulnerability in Debian Debian Linux, published on 4 Jul 2025. 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-2025-38198 in the wild and no public exploit code.

Affected product: Debian Debian 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-2025-38198/ (Markdown: https://insights.sbomify.com/CVE-2025-38198/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38198
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38198
- OSV: https://osv.dev/vulnerability/CVE-2025-38198

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38198/
Summaries are generated and may contain mistakes; the official description above is the record.