# CVE-2026-40003: USB-based arbitrary memory write vulnerability in ZTE ZX297520V3 soc BootROM

> Attackers can achieve unauthorized code execution and bypass Secure Boot via arbitrary memory writes in the ZTE ZX297520V3 BootROM USB download mode.

- **Severity:** Medium 5.1 (`CVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 7 May 2026
- **Updated:** 19 May 2026
- **Also known as:** GHSA-2jfv-r29r-j6wr

## What is CVE-2026-40003?

CVE-2026-40003 is a medium-severity memory corruption vulnerability in ZTE ZX297520V3 BootROM, published on 7 May 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

ZTE ZX297520V3 BootROM contains a vulnerability that allows arbitrary memory writes via USB. Attackers can exploit the lack of target address validation in the USB download mode to write data to any location in BootROM runtime memory, thereby overwriting the stack, hijacking the execution flow, bypassing the Secure Boot signature verification mechanism, and achieving unauthorized code execution.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-40003?

It affects 1 product.


Products: Zte Zx297520v3 Firmware.

## How do I fix CVE-2026-40003?

No fix has been published for CVE-2026-40003 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-40003 being exploited?

There is no known exploitation of CVE-2026-40003 in the wild and no public exploit code.

Public exploit code:

- ZXIC/Sanechips BootROM exploit (github_poc): https://github.com/rva3/CVE-2026-40003

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40003 and fix it if it is affected.

What it is: CVE-2026-40003 is a medium-severity memory corruption vulnerability in ZTE ZX297520V3 BootROM, published on 7 May 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-40003 in the wild and no public exploit code.

Affected product: ZTE ZX297520V3 BootROM. 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-2026-40003/ (Markdown: https://insights.sbomify.com/CVE-2026-40003/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40003
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40003
- OSV: https://osv.dev/vulnerability/CVE-2026-40003

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40003/
Summaries are generated and may contain mistakes; the official description above is the record.