Unauthenticated OS Command Injection in D-Link dnscfg.cgi
CVE-2026-0625 is a critical OS command injection vulnerability in multiple legacy D-Link DSL gateway devices, including reported affected models DSL-2740R, DSL-2640B, DSL-2780B, and DSL-526B. The flaw is in the dnscfg.cgi endpoint that handles DNS configuration parameters. According to the provided content, the CGI library does not properly sanitize or validate user-supplied DNS settings before passing them to underlying system command processing. As a result, an unauthenticated remote attacker can supply crafted DNS configuration input containing shell metacharacters or injected commands and cause arbitrary shell command execution on the device. The same exposed functionality is also associated with unauthenticated DNS configuration changes, enabling DNSChanger-style hijacking. The issue has been reported as actively exploited in the wild, with exploitation evidence observed by the Shadowserver Foundation on 2025-11-27 UTC. All confirmed impacted products are described as end-of-life/end-of-service and no patches are expected for those models.
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Impact, mitigation & remediation
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Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
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Remediation
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Exploits
No valid public exploits. Mallory filtered out 1 candidate as fakes, detection scripts, or README-only repos.
All candidate exploits were filtered out by Mallory's validation.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
45 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A vulnerability affecting discontinued legacy D-Link DSL gateways that is described as being actively exploited as a zero day, with the vendor explicitly stating that no patches would be released.
A command injection vulnerability affecting D-Link DSL routers, reachable via the dnscfg.cgi endpoint, potentially allowing an attacker to execute arbitrary commands on the device.
D-Link legacy DSL router command injection vulnerability under active exploitation enabling unauthenticated RCE.
A zero-day vulnerability in D-Link DSL routers and gateways, tracked as CVE-2026-0625, is being actively exploited. The affected devices are end-of-life and do not have patches available.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.