VulnerabilityPublished 31 Mar 2026

CVE-2026-5177: Totolink A3300R · Command Injection

Affects Totolink A3300RSource CVE Database V5

Public exploit available · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 4.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 2.6% chance of exploitation in 30 days – higher than 85% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
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

Threat metrics

Exploit Maturity: POC

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 31 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
TotolinkA3300R	Affected =17.0.0cu.557_b20221024	Fixed in–

AI-suggested

To mitigate CVE-2026-5177, organizations should first verify if they are using the affected Totolink A3300R firmware version 17.0.0cu.557_b20221024. Since no official patches are currently available, immediate steps include restricting access to the router’s management interface by limiting exposure to trusted internal networks only and disabling remote management features if enabled. Network segmentation should be employed to isolate vulnerable devices from critical assets. Deploying web application firewalls (WAFs) or intrusion prevention systems (IPS) with custom rules to detect and block suspicious requests targeting /cgi-bin/cstecgi.cgi and the rxRate parameter can reduce exploitation risk. Monitoring network traffic for unusual command injection patterns and maintaining robust logging will aid in early detection. Organizations should engage with the vendor for firmware updates and apply patches promptly once released. Additionally, consider replacing affected devices if they cannot be adequately secured or patched in a timely manner. Educating network administrators about this vulnerability and enforcing strong access controls will further reduce attack surface.

Description

A weakness has been identified in Totolink A3300R 17.0.0cu.557_b20221024. Affected by this vulnerability is the function setWiFiBasicCfg of the file /cgi-bin/cstecgi.cgi. Executing a manipulation of the argument rxRate can lead to command injection. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks.

Impact

The impact of CVE-2026-5177 on organizations is significant due to the potential for remote command execution on a widely deployed network device. Exploitation could lead to unauthorized access to the router’s configuration and network traffic, enabling attackers to intercept, modify, or redirect data. This compromises confidentiality and integrity of communications. Attackers could also disrupt network availability by executing commands that degrade or disable router functionality. Additionally, compromised routers can serve as footholds for lateral movement within corporate or home networks, increasing the risk of broader compromise. Organizations relying on Totolink A3300R routers, especially in critical infrastructure or sensitive environments, face increased risk of espionage, data theft, or denial of service. The medium CVSS score reflects moderate impact but the ease of remote exploitation without user interaction elevates the threat level. Without timely patching or mitigation, attackers could leverage this vulnerability to undermine network security and operational stability.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 31 Mar 2026, 14:08 UTC

Technical details

References

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