VulnerabilityPublished 20 Jul 2025Updated 21 Jul 2025

CVE-2025-7881: Mercusys MW301R · Weak Password Recovery

Affects Mercusys MW301RSource CVE Database V5

Public exploit available · CVSS 5.1 Medium.

Data as of 26 Oct 2026, 11:42 UTC

CVSS 4.0 base score

5.1Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: High
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
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: High: The attacker requires privileges that provide significant (e.g., administrative) control over the vulnerable system allowing full access to the vulnerable system’s settings and files.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within 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: None: There is no impact to availability within 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 20 Jul 2025
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

AI-suggested

Immediate mitigation should include isolating the affected Mercusys MW301R devices from critical network segments to limit potential damage if compromised.
Network administrators should monitor network traffic for unusual activity indicative of router compromise, such as unexpected configuration changes or unauthorized access attempts.
Replace affected devices with routers from vendors that provide timely security updates and have a strong security track record.
If replacement is not immediately feasible, disable remote management features on the router to reduce exposure to remote attacks.
Implement strong network segmentation and firewall rules to restrict access to the router's web interface to trusted internal IP addresses only.
Regularly audit and update all network device credentials and ensure that default passwords are changed.
Stay alert for any future patches or advisories from Mercusys or third-party security researchers and apply updates promptly once available.
Consider deploying intrusion detection/prevention systems (IDS/IPS) that can detect exploitation attempts targeting this vulnerability.

Description

A vulnerability was found in Mercusys MW301R 1.0.2 Build 190726 Rel.59423n. It has been declared as problematic. This vulnerability affects unknown code of the component Web Interface. The manipulation of the argument code leads to weak password recovery. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Impact

For European organizations, this vulnerability poses a significant risk especially for small and medium enterprises or home offices using the Mercusys MW301R router, which is an affordable and commonly deployed device in residential and small business environments. Successful exploitation could allow attackers to gain administrative access to the router, enabling them to alter network configurations, intercept or redirect traffic, deploy malware, or create persistent backdoors. This could lead to data breaches, loss of confidentiality, and disruption of network availability. Given the router's role as a network gateway, compromise could extend to connected devices, increasing the attack surface. Organizations relying on these routers without additional network segmentation or monitoring are particularly vulnerable. The lack of vendor response and patch availability exacerbates the risk, as affected devices remain exposed. This vulnerability could also be leveraged in broader campaigns targeting IoT and network infrastructure devices in Europe, potentially impacting critical infrastructure if such devices are used in sensitive environments.

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 28 Jul 2025, 01:03 UTC

Technical details

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