CVE-2026-42374
D-Link DIR-600L B1 Hardcoded Telnet Backdoor Credentials
Description
D-Link DIR-600L Hardware Revision B1 (End-of-Life) contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /bin/telnetd.sh with the username "Alphanetworks" and the static password "wrgn61_dlwbr_dir600L" read from /etc/alpha_config/image_sign. The custom telnetd binary accepts a -u user:password flag, and the custom login binary uses strcmp() to validate credentials. Successful authentication grants an unauthenticated attacker on the local network a root shell with full administrative control. The device has reached End-of-Life (EOL) and will not receive patches.
INFO
Published Date :
May 4, 2026, 5:16 p.m.
Last Modified :
May 4, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
33c584b5-0579-4c06-b2a0-8d8329fcab9c
Affected Products
The following products are affected by CVE-2026-42374
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 33c584b5-0579-4c06-b2a0-8d8329fcab9c |
Solution
- Replace the affected device immediately.
- Do not use EOL devices.
- Isolate the device from the network.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42374.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42374 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42374
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42374 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42374 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 33c584b5-0579-4c06-b2a0-8d8329fcab9c
May. 04, 2026
Action Type Old Value New Value Added Tag unsupported-when-assigned Added Description D-Link DIR-600L Hardware Revision B1 (End-of-Life) contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /bin/telnetd.sh with the username "Alphanetworks" and the static password "wrgn61_dlwbr_dir600L" read from /etc/alpha_config/image_sign. The custom telnetd binary accepts a -u user:password flag, and the custom login binary uses strcmp() to validate credentials. Successful authentication grants an unauthenticated attacker on the local network a root shell with full administrative control. The device has reached End-of-Life (EOL) and will not receive patches. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-798 Added Reference https://www.securin.io/zero-day/cve-2026-42374-hardcoded-telnet-backdoor-in-d-link-dir-600l-b1-end-of-life- -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 04, 2026
Action Type Old Value New Value Added Reference https://www.securin.io/zero-day/cve-2026-42374-hardcoded-telnet-backdoor-in-d-link-dir-600l-b1-end-of-life-