# CVE-2026-23474: mtd: Avoid boot crash in RedBoot partition table parser

> A buffer overflow in the Linux kernel's RedBoot partition parser causes a boot crash when specific compiler fortification settings are enabled.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 3 Apr 2026
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2026-23474, DEBIAN-CVE-2026-23474, GHSA-hvxh-97j9-4hcx, ROOT-OS-DEBIAN-11-CVE-2026-23474, ROOT-OS-DEBIAN-12-CVE-2026-23474, ROOT-OS-DEBIAN-13-CVE-2026-23474, ROOT-OS-UBUNTU-2204-CVE-2026-23474, ROOT-OS-UBUNTU-2404-CVE-2026-23474, UBUNTU-CVE-2026-23474

## What is CVE-2026-23474?

CVE-2026-23474 is a medium-severity memory corruption vulnerability in Linux kernel, published on 3 Apr 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:

mtd: Avoid boot crash in RedBoot partition table parser

Given CONFIG_FORTIFY_SOURCE=y and a recent compiler,
commit 439a1bcac648 ("fortify: Use __builtin_dynamic_object_size() when
available") produces the warning below and an oops.

    Searching for RedBoot partition table in 50000000.flash at offset 0x7e0000
    ------------[ cut here ]------------
    WARNING: lib/string_helpers.c:1035 at 0xc029e04c, CPU#0: swapper/0/1
    memcmp: detected buffer overflow: 15 byte read of buffer size 14
    Modules linked in:
    CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.19.0 #1 NONE

As Kees said, "'names' is pointing to the final 'namelen' many bytes
of the allocation ... 'namelen' could be basically any length at all.
This fortify warning looks legit to me -- this code used to be reading
beyond the end of the allocation."

Since the size of the dynamic allocation is calculated with strlen()
we can use strcmp() instead of memcmp() and remain within bounds.

## Which versions are affected by CVE-2026-23474?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23474?

Apply the vendor's patch.

## Is CVE-2026-23474 being exploited?

There is no known exploitation of CVE-2026-23474 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23474 and fix it if it is affected.

What it is: CVE-2026-23474 is a medium-severity memory corruption vulnerability in Linux kernel, published on 3 Apr 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-2026-23474 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-23474/ (Markdown: https://insights.sbomify.com/CVE-2026-23474/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23474
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23474
- OSV: https://osv.dev/vulnerability/CVE-2026-23474

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23474/
Summaries are generated and may contain mistakes; the official description above is the record.