What is the CVSS score of CVE-2026-4497?

CVE-2026-4497 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:L/VA:L/SC:N/SI:N/SA:N/E:P. EPSS exploitation probability: 1.9%.

Is there a public PoC exploit available for CVE-2026-4497?

Yes, a public proof-of-concept exploit is available for CVE-2026-4497. Prioritise patching immediately. EPSS: 1.9%.

How to fix or mitigate CVE-2026-4497?

Within 24 hours: Identify all Totolik WA300 devices in inventory and isolate affected units from production networks if possible; create an incident response plan. Within 7 days: Implement network segmentation to restrict router administrative access, deploy monitoring for suspicious command patterns, and contact Totolink support for patch availability timeline. Within 30 days: Develop a device replacement or firmware upgrade plan once patches are released; consider alternative router models as interim solution if business continuity permits.

Wa300 CVE-2026-4497

EUVD-2026-13770 MEDIUM

OS Command Injection (CWE-78)

2026-03-20 VulDB

Command Injection Wa300 TOTOLINK

5.5

CVSS 4.0 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-78 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V1 - Encoding and Sanitization OS command sanitization, avoid shell exec MITRE ATT&CK 2 techniques across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	This vulnerability presents significant real-world risk. The CVSS v3.1 score of 7.3 (High) accurately reflects the severity, with the attack vector being network-based (AV:N), low attack complexity (AC:L), and requiring no privileges (PR:N) or user interaction (UI:N). The availability of a public proof-of-concept exploit dramatically increases the likelihood of exploitation, as attackers can leverage existing code rather than developing their own. The vulnerability allows partial confidentiality, integrity, and availability impact (C:L/I:L/A:L), meaning attackers achieve full device compromise typical of command injection. Home and small business users of these routers are particularly at risk since Totolink devices often lack automatic update mechanisms and may remain unpatched indefinitely. This should be considered a high-priority remediation item for any organization using affected devices.
Exploit ScenarioDerived	An attacker on the internet scans for exposed Totolink WA300 devices using tools like Shodan or Censys to identify devices with accessible web management interfaces. Using the publicly available proof-of-concept exploit, the attacker crafts a malicious HTTP request to the /cgi-bin/cstecgi.cgi endpoint targeting the recvUpgradeNewFw function with specially crafted parameters containing shell metacharacters and commands. Without authentication, the injected commands execute with the privileges of the web server process, allowing the attacker to establish persistence, exfiltrate network traffic, pivot to internal network resources, or enlist the device in a botnet for DDoS attacks.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

No patch listed yet 1.9% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 20, 2026

A critical OS command injection vulnerability exists in Totolink WA300 router firmware version 5.2cu.7112_B20190227, specifically in the recvUpgradeNewFw function within /cgi-bin/cstecgi.cgi. An unauthenticated remote attacker can exploit this flaw to execute arbitrary operating system commands on the affected device. A public proof-of-concept exploit has been released on GitHub, significantly lowering the barrier to exploitation and increasing real-world risk.

RemediationAI

Users should immediately check the Totolink vendor website at https://www.totolink.net/ for updated firmware versions that address this command injection vulnerability and upgrade to the latest available firmware for the WA300 model. Until patching is feasible, implement network-level mitigations by restricting administrative access to the device management interface to trusted IP addresses only, disabling remote management features if not required, and placing the device behind a firewall that blocks external access to the web interface on ports 80 and 443. Consider replacing the device with a more actively maintained alternative if Totlink has not released security updates, as the presence of a public exploit (https://github.com/user-attachments/files/25790616/Unauthenticated.Remote.Code.Execution.in.TOTOLINK.WA300.via.Command.Injection.in.recvUpgradeNewFw.zip) makes continued use without patches extremely risky.

Affected VersionsENISA

WA300 5.2cu.7112_B20190227

Affected Packages

euvd wa300 no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability affects the Totolink WA300 wireless access point (CPE: cpe:2.3:a:totolink:wa300), a consumer networking device. The root cause is CWE-78 (OS Command Injection), where user-supplied input to the recvUpgradeNewFw function in the /cgi-bin/cstecgi.cgi CGI script is not properly sanitized before being passed to system shell commands. This is a common vulnerability pattern in embedded device firmware where developer-implemented CGI scripts handle firmware upgrade operations without adequate input validation. The vulnerability exists in the web management interface, allowing network-accessible exploitation without prior authentication.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 5.5 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Vulnerable system: Confidentiality

Low

Vulnerable system: Integrity

Low

Vulnerable system: Availability

Low

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

Lifecycle Timeline

CVSS changed

Apr 29, 2026 - 01:11 NVD

6.9 (MEDIUM) 5.5 (MEDIUM)

PoC Detected

Apr 03, 2026 - 11:31 vuln.today

Public exploit code

CVE Published

Mar 20, 2026 - 19:02 nvd

MEDIUM 6.9

DescriptionCVE.org

A vulnerability was determined in Totolink WA300 5.2cu.7112_B20190227. Affected by this issue is the function recvUpgradeNewFw of the file /cgi-bin/cstecgi.cgi. This manipulation causes os command injection. Remote exploitation of the attack is possible. The exploit has been publicly disclosed and may be utilized.

Executive ViewAI

Why It Matters

An unauthenticated remote code execution vulnerability affecting Totolink WA300 routers allows attackers to take complete control of affected devices without credentials. With a public exploit available and no patch currently available, any organization using this router model faces immediate risk of network compromise, data theft, and lateral movement into internal systems.

Business Impact: Severe

Compensating Controls

Implement network access controls to restrict WAN access to the router's management interface; deploy a WAF or intrusion prevention system (IPS) to filter malicious HTTP requests to /cgi-bin/cstecgi.cgi with recvUpgradeNewFw parameters; disable unnecessary CGI services if possible; segment the router on a separate management network with strict ingress/egress filtering; monitor for exploitation attempts using signature-based detection rules; consider disabling remote management features entirely and using out-of-band administration channels.

Threat Intelligence Overview

EPSS Score

1.9%

Top 17% exploitable

Exploit

POC

Public exploit code exists

Data Quality

7 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

Vulnrichment

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity MEDIUM

CISA KEV No

Public POC Yes

EPSS 1.9%

Patch available No

Active threat No

Deciding rule

MEDIUM severity (CVSS 4.0-6.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.