4G03 Pro CVE-2026-5527

Q: What is the CVSS score of CVE-2026-5527?

CVE-2026-5527 has a CVSS 4.0 base score of 5.5 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

EUVD-2026-19003 MEDIUM

Use of Hard-coded Cryptographic Key (CWE-321)

2026-04-04 VulDB

GHSA-pgjq-fxv2-9p7v

Information Disclosure Tenda 4G03 Pro

5.5

CVSS 4.0 · Vendor: VulDB

Severity by source

Vendor (VulDB) PRIMARY

5.5 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from Vendor (VulDB) · only source for this CVE.

CVSS VectorVendor: VulDB

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

EUVD ID Assigned

Apr 04, 2026 - 23:30 euvd

EUVD-2026-19003

Analysis Generated

Apr 04, 2026 - 23:30 vuln.today

CVE Published

Apr 04, 2026 - 23:15 nvd

MEDIUM 5.5

DescriptionCVE.org

A weakness has been identified in Tenda 4G03 Pro 1.0/1.0re/01.bin/04.03.01.53. Affected by this issue is some unknown functionality of the file /etc/www/pem/server.key of the component ECDSA P-256 Private Key Handler. This manipulation causes use of hard-coded cryptographic key . It is possible to initiate the attack remotely.

AnalysisAI

Tenda 4G03 Pro wireless router contains a hard-coded ECDSA P-256 private cryptographic key in the /etc/www/pem/server.key file, enabling remote attackers to decrypt HTTPS communications and potentially impersonate the device without authentication. The vulnerability affects firmware versions 1.0, 1.0re, 01.bin, and 04.03.01.53, and carries a CVSS score of 5.3 with proof-of-concept exploitation likely (E:P rating). No public exploit code has been independently confirmed at the time of this analysis.

Technical ContextAI

The vulnerability stems from use of hard-coded cryptographic material (CWE-321) in the Tenda 4G03 Pro router's ECDSA P-256 implementation. The private key is embedded in the firmware file /etc/www/pem/server.key, which is used for TLS/SSL server certificate operations. When a cryptographic key is embedded statically across all device instances, any attacker possessing the firmware image or accessing the key through the web-accessible path can derive the private key material, compromising all confidentiality guarantees of encrypted communications between the device and clients. ECDSA P-256 (also known as secp256r1) is a standard elliptic-curve cryptography algorithm; the weakness is not in the algorithm itself but in the deployment practice of hard-coding the key.

RemediationAI

Organizations should contact Tenda directly at https://www.tenda.com.cn/ for a patched firmware release, as no specific fixed firmware version has been confirmed in available data. If a patch is released, perform a factory reset and upgrade the device to the latest firmware version available from Tenda's support portal. As an interim workaround, if the device is accessible via SSH or web administration interface, users may attempt to regenerate the server certificate and private key using device administration tools, though this depends on available device capabilities and may require firmware modification. Restrict network access to the device's web administration interface using firewall rules, and disable remote administration features if not operationally required. Monitor Tenda security advisories at https://www.tenda.com.cn/ for official patch availability.