CyberSecBulletin
CVE-2026-118579NVD status: Deferred

DIR-505: Hidden Functionality

CVE-2026-118579 is a critical-severity hidden functionality vulnerability in DIR-505 from D-Link, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected DIR-505 versions: 1.10B02. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of DIR-505 you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
D-LinkDIR-5051.10B02Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vuldb.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.9HighCNA (vuldb.com)
CVSS 3.19.8CriticalCNA (vuldb.com)
CVSS 2.010.0HighCNA (vuldb.com)

Official description

A weakness has been identified in D-Link DIR-505 1.10B02. The impacted element is the function main of the file /secmark1524.cgi of the component Web Management CGI. This manipulation of the argument accu/pass/code/hash/cmds causes backdoor. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Hidden Functionality

The product contains functionality that is not documented, not part of the specification, and not accessible through an interface or command sequence that is obvious to the product's users or administrators.

How developers prevent this class of flaw

  • Always verify the integrity of the product that is being installed.

More Hidden Functionality vulnerabilities (CWE-912)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in DIR-505

All DIR-505 vulnerabilities

Recent Hidden Functionality vulnerabilities

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