# CVE-2026-20431: Denial of service in MediaTek chipset

> A logic error in MediaTek modem firmware allows remote attackers to cause a system crash via a rogue base station, requiring no user interaction.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 7 Apr 2026
- **Updated:** 7 Apr 2026
- **Also known as:** A-480745369, ASB-A-480745369, GHSA-6pq9-8556-qr3w, M-MOLY01106496

## What is CVE-2026-20431?

CVE-2026-20431 is a medium-severity denial of service vulnerability in MediaTek, Inc. MediaTek chipset, published on 7 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In Modem, there is a possible system crash due to a logic error. This could lead to remote denial of service, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01106496; Issue ID: MSV-4467.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-20431?

It affects 19 products.


Products: Mediatek Mt6813 Firmware, Mediatek Mt6815 Firmware, Mediatek Mt6835 Firmware, Mediatek Mt6878 Firmware, Mediatek Mt6897 Firmware, Mediatek Mt6899 Firmware, Mediatek Mt6986 Firmware, Mediatek Mt6991 Firmware, Mediatek Mt6993 Firmware, Mediatek Mt8668 Firmware, Mediatek Mt8676 Firmware, Mediatek Mt8678 Firmware, Mediatek Mt8755 Firmware, Mediatek Mt8775 Firmware, Mediatek Mt8792 Firmware, Mediatek Mt8793 Firmware, Mediatek Mt8863 Firmware, Mediatek Mt8873 Firmware, Mediatek Mt8883 Firmware.

## How do I fix CVE-2026-20431?

Apply the vendor's patch.

## Is CVE-2026-20431 being exploited?

There is no known exploitation of CVE-2026-20431 in the wild and no public exploit code.

## Other vulnerabilities in MediaTek, Inc. MediaTek chipset

- [CVE-2026-20476](https://insights.sbomify.com/CVE-2026-20476/): Memory corruption in MediaTek chipset (medium 5.5)
- [CVE-2026-20490](https://insights.sbomify.com/CVE-2026-20490/): Denial of service in MediaTek chipset (medium 4.4)
- [CVE-2026-20446](https://insights.sbomify.com/CVE-2026-20446/): Integer overflow in MediaTek chipset (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20431 and fix it if it is affected.

What it is: CVE-2026-20431 is a medium-severity denial of service vulnerability in MediaTek, Inc. MediaTek chipset, published on 7 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-2026-20431 in the wild and no public exploit code.

Affected product: MediaTek, Inc. MediaTek chipset. 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-2026-20431/ (Markdown: https://insights.sbomify.com/CVE-2026-20431/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20431
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20431
- OSV: https://osv.dev/vulnerability/CVE-2026-20431

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20431/
Summaries are generated and may contain mistakes; the official description above is the record.