CVE-2026-3040: DrayTek Vigor 300B Web Management uploadlangs cgiGetFile os command injection

Description

A vulnerability was identified in DrayTek Vigor 300B up to 1.5.1.6. This affects the function cgiGetFile of the file /cgi-bin/mainfunction.cgi/uploadlangs of the component Web Management Interface. The manipulation of the argument File leads to os command injection. The attack may be initiated remotely. The exploit is publicly available and might be used. The vendor confirms that "300B is EoL, and this is an authenticated vulnerability. We don't plan to fix it." This vulnerability only affects products that are no longer supported by the maintainer.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack vector

Network

Complexity

Low

Privileges

High

User interaction

None

Confidentiality

High

Integrity

High

Availability

High

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)10.1% · higher than 96% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

V3

Vigor 300B · DrayTek

1.5.1.0; 1.5.1.1; 1.5.1.2; 1.5.1.3; 1.5.1.4; 1.5.1.5; +1 more · source: vendor

VF

Vigor300b Firmware · Draytek

through 1.5.1.6 · source: NVD