What is CVE-2026-40003?

CVE-2026-40003 is a medium-severity vulnerability in Zte Zx297520v3, classified under Out-of-bounds Write. CVSS score: 5.1/10. Published 2026-05-07.

How severe is CVE-2026-40003?

Medium severity. CVSS v3 base score is 5.1 out of 10.

Is CVE-2026-40003 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Zte Zx297520v3

CVE-2026-40003

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, ther…

Vulnerability class: Buffer Overflow

EPSS: 0.000 (1.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.1 (Medium). Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:L.

Affected products

Zte Zx297520v3
Zte Zx297520v3 Bootrom — versions 7520V3 chip
Zte Zx297520v3_firmware

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

rva3/CVE-2026-40003

References

psirt@zte.com.cn (Vendor Advisory)

Frequently asked questions

What is CVE-2026-40003?: CVE-2026-40003 is a medium-severity vulnerability in Zte Zx297520v3, classified under Out-of-bounds Write. CVSS score: 5.1/10. Published 2026-05-07.
How severe is CVE-2026-40003?: Medium severity. CVSS v3 base score is 5.1 out of 10.
Is CVE-2026-40003 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.