Where
-Infinity
0
Severity
8.8
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)V1200909 allows unauthenticated brute-force attacks via the TDDP password change endpoint (code=10), which lacks the rate limiting applied to the login endpoint (code=7). An attacker on the adjacent network can attempt unlimited passwords without triggering account lockout.

First published (updated )
Severity
8.1
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)V1200909 exposes 15 of 18 UPnP IGD actions without authentication on port 1900, including AddPortMapping and GetExternalIPAddress. UPnP is enabled by default through the admin interface, allowing any unauthenticated LAN device to create arbitrary port forwarding rules and access WAN traffic statistics.

First published (updated )
Severity
7.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)V1200909 uses a static authentication nonce that does not change between requests from the same source IP. Combined with the predictable XOR-based password encoding (securityEncode function), this allows an attacker to reverse captured authentication tokens to recover the plaintext password.

First published (updated )
Severity
7.3
Infoleak
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Mercusys AC12G (EU) V1 with firmware AC12G(EU)V1200909 returns 128 bytes of uninitialized buffer when receiving POST requests without SOAPAction header on UPnP port 1900, exposing internal memory to unauthenticated adjacent network attackers.

First published (updated )
Severity
7.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)V1200909 encrypts configuration backups with a hardcoded DES key using single DES in ECB mode. An attacker who obtains a backup file can decrypt it to recover all stored credentials including admin password, WiFi PSK, and DDNS credentials.

First published (updated )
Severity
6.5
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)V1200909 is vulnerable to a HTTP denial of service via a low number of crafted incomplete HTTP requests, causing a persistent crash that requires physical power cycling to recover.

First published (updated )
Severity
6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)V1200909 does not validate the HTTP Host header, enabling DNS rebinding attacks. An external attacker can rebind a domain to the router's internal IP address, extending the CORS wildcard vulnerability (Access-Control-Allow-Origin: ) to internet-originated attacks.

First published (updated )
Severity
6.4
CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Mercusys AC12G (EU) V1 with firmware AC12G(EU)V1200909 enables WPS 2.0 by default with a weak lockout policy (60-second lockout after 10 attempts).

First published (updated )
Severity
5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Mercusys AC12G (EU) V1 with firmware AC12G(EU)V1200909 transmits DDNS credentials over plaintext HTTP with only Base64 encoding. The firmware contains no TLS implementation, allowing man-in-the-middle interception of DDNS service credentials.

First published (updated )
Severity
5.9
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Mercusys AC12G (EU) V1 with firmware AC12G(EU)V1200909 contains hardcoded WiFi driver credentials including a RADIUS shared secret, WPS test key, and default PSK embedded in the production firmware binary.

First published (updated )
Severity
4.3
Infoleak
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)V1200909 discloses kernel memory layout via the UPnP GetStatusInfo action. An unauthenticated attacker on the adjacent network can obtain a raw MIPS KSEG0 kernel pointer, revealing kernel memory layout and aiding further exploitation.

First published (updated )
Severity
4.3
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Mercusys AC12G (EU) V1 with firmware AC12G(EU)V1200909 returns 128 bytes of uninitialized internal buffer contents when receiving HTTP POST requests to undefined paths, exposing server state to unauthenticated adjacent network attackers.

First published (updated )
Severity
4.3
Infoleak
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Mercusys AC12G (EU) V1 with firmware AC12G(EU)V1200909 exposes an undocumented /agileconfigreset endpoint that returns internal buffer contents to unauthenticated attackers on the adjacent network.

First published (updated )
Severity
4.3
Infoleak
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Mercusys AC12G (EU) V1 with firmware AC12G(EU)V1200909 responds to version.bind CHAOS TXT queries, disclosing the DNS resolver software version (unbound 1.22.0), aiding targeted attacks against known vulnerabilities.

First published (updated )

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203