Medium

CVE-2026-5527 — Tenda 4G03 Pro ECDSA P-256 Private Key server.key hard-coded key

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.

Published Apr 4, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulDB

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.6% (30-day exploitation probability)+7
Technical severity (medium)+3
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.57%

ahead of 46% of scored CVEs · Oct 15, 2026

Affects

Tenda

4G03 Pro and 1 more

CVSS base

5.3

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Tenda 4G03 Pro, Tenda 4g03 Pro Firmware).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Tenda	4G03 Pro	version 1.0version 1.0reversion 01.binversion 04.03.01.53	Vulnerable	CVE Program (cve.org) e CISA ADP
Tenda	4g03 Pro Firmware	version 04.03.01.53	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
6.9	CVSS 4.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
5.5	CVSS 4.0	Medium	—	—	cna@vuldb.com via NIST National Vulnerability Database
5.3	CVSS 3.1	Medium	3.9	1.4	cna@vuldb.com via NIST National Vulnerability Database
5.3	CVSS 3.1	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
5.3	CVSS 3.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
5.0	CVSS 2.0	Medium	10.0	2.9	cna@vuldb.com via NIST National Vulnerability Database
5.0	CVSS 2.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N (score shown at the top: cna@vuldb.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-320

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.57%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · tenda/4g03 pro
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 5.3
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Apr 4, 2026 · VulDB

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

vuldb.com/vuln/355280
Third Party Advisory, VDB Entry, vdb-entry, NIST National Vulnerability Database
vuldb.com/vuln/355280/cti
Permissions Required, VDB Entry, signature, permissions-required, NIST National Vulnerability Database
vuldb.com/submit/782053
Third Party Advisory, VDB Entry, third-party-advisory, NIST National Vulnerability Database
www.tenda.com.cn/
Product, product, NIST National Vulnerability Database

Elsewhere on this site

Tenda
every CVE for this vendor

CWE-320
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-5526 Tenda 4G03 Pro httpd access control Apr 4, 2026
High CVE-2025-15371 Tenda i24 Shadow File hard-coded credentials Dec 30, 2025

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-5527 is "Tenda 4G03 Pro ECDSA P-256 Private Key server.key hard-coded key", rated Medium. It affects 4G03 Pro (Tenda); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 0.57% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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