CVE-2026-42375: D-Link DIR-600L Firmware · Use of Hard-coded Credentials
Affects D-Link DIR-600L FirmwareSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · end of life, no fix coming : replace or isolate D-Link DIR-600L Firmware; no fix will be released.
Data as of 31 Oct 2026, 20:20 UTC
Contested
Critical score, yet low EPSS after six months- EPSS
- 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- None coming – the product is end of life
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 4 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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), the Metasploit, Exploit-DB and nuclei-templates index as of 31 Oct 2026.
What to do
No fix will be released: D-Link DIR-600L Firmware is end of life. Replace it, or isolate it from untrusted networks until you can.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| D-LinkDIR-600L Firmware | Affected
| Fixed in– |
AI-suggested
Mitigation requires replacing the affected hardware with a supported device that does not contain this vulnerability. Network segmentation to isolate the device and disabling telnet access where possible may reduce exposure, but these are partial mitigations. Users should consider device replacement as the primary remediation.
Description
The D-Link DIR-600L Hardware Revision A1 firmware contains a hardcoded telnet backdoor with static credentials. This backdoor launches a telnet daemon at boot, allowing anyone on the local network to authenticate using the fixed username "Alphanetworks" and password "wrgn35_dlwbr_dir600l". Successful login grants root shell access, providing full administrative control. The device is End-of-Life and will not receive patches to address this vulnerability. The CVSS score is 9.8, indicating a critical severity level.