# CVE-2026-20500: Denial of service in MediaTek chipset

> A local attacker with user privileges can cause a system crash in MediaTek chipsets via improper input validation in the Modem component.

- **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:** 7 Sep 2026
- **Updated:** 7 Sep 2026
- **Also known as:** A-528209857, ASB-A-528209857, GHSA-3wwc-gvmj-fpx5, M-MOLY01810811

## What is CVE-2026-20500?

CVE-2026-20500 is a medium-severity denial of service vulnerability in MediaTek, Inc. MediaTek chipset, published on 7 Sep 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 improper input validation. This could lead to local denial of service with User execution privileges needed. User interaction is needed for exploitation. Patch ID: MOLY01810811; Issue ID: MSV-9232.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-20500?

It affects 22 products.


Products: Mediatek Mt2716 Firmware, Mediatek Mt6835 Firmware, Mediatek Mt6858 Firmware, Mediatek Mt6878 Firmware, Mediatek Mt6881 Firmware, Mediatek Mt6897 Firmware, Mediatek Mt6899 Firmware, Mediatek Mt6982vb Firmware, Mediatek Mt6986 Firmware, Mediatek Mt6988 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 and 2 more.

## How do I fix CVE-2026-20500?

Apply the vendor's patch.

## Is CVE-2026-20500 being exploited?

There is no known exploitation of CVE-2026-20500 in the wild and no public exploit code.

## Other vulnerabilities in MediaTek, Inc. MediaTek chipset

- [CVE-2026-20519](https://insights.sbomify.com/CVE-2026-20519/): Memory corruption in MediaTek chipset (high 7.5)
- [CVE-2026-20520](https://insights.sbomify.com/CVE-2026-20520/): Memory corruption in MediaTek chipset (high 7.5)
- [CVE-2026-20526](https://insights.sbomify.com/CVE-2026-20526/): Memory corruption in MediaTek chipset (high 7.5)
- [CVE-2026-20543](https://insights.sbomify.com/CVE-2026-20543/): Information disclosure in MediaTek chipset (medium 5.5)
- [CVE-2026-20525](https://insights.sbomify.com/CVE-2026-20525/): Denial of service in MediaTek chipset (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20500 and fix it if it is affected.

What it is: CVE-2026-20500 is a medium-severity denial of service vulnerability in MediaTek, Inc. MediaTek chipset, published on 7 Sep 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-2026-20500 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-2026-20500/ (Markdown: https://insights.sbomify.com/CVE-2026-20500/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20500
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20500
- OSV: https://osv.dev/vulnerability/CVE-2026-20500

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20500/
Summaries are generated and may contain mistakes; the official description above is the record.