Raw 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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-5527 is a medium-severity Use of Hard-coded Cryptographic Key (CWE-321) vulnerability in Tenda 4G03 Pro Firmware. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Private Keys (T1552.004); ranked at the 36th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-12 (Cryptographic Key Establishment and Management) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19003
Vulnerability Data
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…
more
is possible to initiate the attack remotely.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Requiring cryptographic keys to be established and managed according to defined requirements prevents developers from embedding static unchangeable keys.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-SDLC activities such as code review and secret scanning directly prevent embedding static keys.
Data-at-rest protection policies require proper key management and therefore discourage hard-coded keys.
Data-in-transit protection similarly depends on non-hard-coded keys for encryption.
Configuration baselines and reviews can prohibit hard-coded keys in deployed artifacts.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Key-management controls that govern generation, rotation and protection of keys make the use of embedded hard-coded cryptographic keys less likely and easier to detect.