CVE-2026-0625

Critical

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).

SeverityCritical
CVSS9.3
Exploit probability—
ProductDSL-2640B
PublishedJan 5, 2026
First seenJan 5, 2026

How to fix

Affected products

ProductAffected versionsFixed in
D-Link DSL-2640B0—
D-Link DSL-2740R0—
D-Link DSL-2780B0—
D-Link DSL-526B0—
D-Link DSL-2640T0—
D-Link DSL-5000—
D-Link DSL-500G0—
D-Link DSL-502G0—
D-Link DIR-905L0—
D-Link DIR-6000—
D-Link DIR-6080—
D-Link DIR-6100—
D-Link DIR-6110—
D-Link DIR-6150—
D-Link DNS-3200—
D-Link DNS-3250—
D-Link DNS-3450—

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