D-Link DSL/DIR/DNS Authentication Bypass via DNS Configuration Endpoint

Summary

CVE	CVE-2026-0625
State	PUBLISHED
Assigner	VulnCheck
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-01-05 22:15:54 UTC
Updated	2026-04-15 00:35:42 UTC
Description	Multiple D-Link DSL/DIR/DNS devices contain an authentication bypass and improper access control vulnerability in the dnscfg.cgi endpoint that allows an unauthenticated attacker to access DNS configuration functionality. By directly requesting this endpoint, an attacker can modify the device’s DNS settings without valid credentials, enabling DNS hijacking (“DNSChanger”) attacks that redirect user traffic to attacker-controlled infrastructure. In 2019, D-Link reported that this behavior was leveraged by the "GhostDNS" malware ecosystem targeting consumer and carrier routers. All impacted products were subsequently designated end-of-life/end-of-service, and no longer receive security updates. Exploitation evidence was observed by the Shadowserver Foundation on 2025-11-27 (UTC).

Risk And Classification

Primary CVSS: v4.0 9.3 CRITICAL from [email protected]

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.008250000 probability, percentile 0.746880000 (date 2026-05-27)

Problem Types: CWE-306 | CWE-306 CWE-306 Missing Authentication for Critical Function

Version	Source	Type	Score	Severity	Vector
4.0	[email protected]	Secondary	9.3	CRITICAL	`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/C...`
4.0	CNA	CVSS	9.3	CRITICAL	`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

CVSS v4.0 Breakdown

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Confidentiality

High

Integrity

High

Availability

High

Sub Conf.

None

Sub Integrity

None

Sub Availability

None

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	D-Link	DSL-2640B	affected	Not specified
CNA	D-Link	DSL-2740R	affected	Not specified
CNA	D-Link	DSL-2780B	affected	Not specified
CNA	D-Link	DSL-526B	affected	Not specified
CNA	D-Link	DSL-2640T	affected	Not specified
CNA	D-Link	DSL-500	affected	Not specified
CNA	D-Link	DSL-500G	affected	Not specified
CNA	D-Link	DSL-502G	affected	Not specified
CNA	D-Link	DIR-905L	affected	Not specified
CNA	D-Link	DIR-600	affected	Not specified
CNA	D-Link	DIR-608	affected	Not specified
CNA	D-Link	DIR-610	affected	Not specified
CNA	D-Link	DIR-611	affected	Not specified
CNA	D-Link	DIR-615	affected	Not specified
CNA	D-Link	DNS-320	affected	Not specified
CNA	D-Link	DNS-325	affected	Not specified
CNA	D-Link	DNS-345	affected	Not specified

References

Reference	Source	Link	Tags
supportannouncement.us.dlink.com/security/publication.aspx	[email protected]	supportannouncement.us.dlink.com
www.vulncheck.com/advisories/dlink-dsl-command-injection-via-dns-configuration-...	[email protected]	www.vulncheck.com
supportannouncement.us.dlink.com/announcement/publication.aspx	[email protected]	supportannouncement.us.dlink.com
supportannouncement.us.dlink.com/security/publication.aspx	[email protected]	supportannouncement.us.dlink.com
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: The Shadowserver Foundation (en)

CNA: VulnCheck (en)

Additional Advisory Data

Solutions

CNA: D-Link Systems, Inc. recommends retiring these products and replacing them with products that receive firmware updates.

There are currently no legacy QID mappings associated with this CVE.