CVE-2026-42375: D-Link DIR-600L Hardware Revision A1 (End-of-Life) contains a hardcoded telnet backdoor. The device starts a telnet…
CVE-2026-42375 · Severity: critical · CVSS 9.8 · Published 2026-05-04
D-Link DIR-600L Hardware Revision A1 (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 "wrgn35_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.
No. Junglewise Threat Intelligence has no report of CVE-2026-42375 being exploited in the wild.
How severe is CVE-2026-42375?
Critical severity, with a CVSS score of 9.8, published 4 May 2026.
Which products and versions are affected?
Dlink Dir-600l, Dlink Dir-600l Firmware. The advisory does not name versions.
Is there a fix for CVE-2026-42375?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-42375?
Check whether you run Dlink Dir-600l or Dlink Dir-600l Firmware. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.