CyberSecBulletin
CVE-2026-71925NVD status: Deferred

VigorSwitch G2540xs: Improper Neutralization of Special Elements used in an OS Command

Published Updated By the CyberSecBulletin desk

CVE-2026-71925 is a high-severity improper neutralization of special elements used in an OS command vulnerability in VigorSwitch G2540xs from DrayTek, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. The record lists version 3.9.10 as the first without the flaw, so updating VigorSwitch G2540xs to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.27% chance of exploitation within 30 days, higher than 83% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update VigorSwitch G2540xs to 3.9.10 or a later version.
  2. Update VigorSwitch P2540xs to 3.9.10 or a later version.
  3. Update VigorSwitch FX2120 to 3.9.10 or a later version.
  4. Read the advisory on draytek.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
DrayTekVigorSwitch G2540xsbefore 3.9.103.9.10
DrayTekVigorSwitch P2540xsbefore 3.9.103.9.10
DrayTekVigorSwitch FX2120before 3.9.103.9.10
DrayTekVigorSwitch G2282xbefore 2.10.62.10.6
DrayTekVigorSwitch P2282xbefore 2.10.62.10.6
DrayTekVigorSwitch Q2300xbefore 2.10.72.10.7
DrayTekVigorSwitch PQ2300xbbefore 2.10.72.10.7
DrayTekVigorSwitch G2542xbefore 3.10.63.10.6
DrayTekVigorSwitch P2542xbefore 3.10.63.10.6
DrayTekVigorSwitch P2542xhbefore 3.10.63.10.6
DrayTekVigorSwitch PX2060before 2.9.102.9.10
DrayTekVigorSwitch G1280before 2.9.102.9.10
DrayTekVigorSwitch P1280before 2.9.102.9.10
DrayTekVigorSwitch P1281xbefore 2.9.102.9.10
DrayTekVigorSwitch G1282before 2.9.102.9.10
DrayTekVigorSwitch P1282before 2.9.102.9.10
DrayTekVigorSwitch G2121before 2.9.102.9.10
DrayTekVigorSwitch P2121before 2.9.102.9.10
DrayTekVigorSwitch PQ2121xbefore 2.9.102.9.10
DrayTekVigorSwitch Q2121xbefore 2.9.102.9.10
DrayTekVigorSwitch G2280xbefore 2.9.102.9.10
DrayTekVigorSwitch P2280xbefore 2.9.102.9.10
DrayTekVigorSwitch Q2200xbefore 2.9.102.9.10
DrayTekVigorSwitch PQ2200xbbefore 2.9.102.9.10
DrayTekVigorSwitch G2100before 2.9.102.9.10

Version data comes from the organisation that assigned the CVE; 3 further products are omitted here. 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
HighAdministrator-level access is required first.
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:H/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.6HighCNA (vulncheck.com)
CVSS 3.17.2HighCNA (vulncheck.com)

Official description

Multiple DrayTek VigorSwitch models contain a command injection vulnerability in the getDetail function. The vulnerability is caused by insufficient filtering of the username and password fields before command execution. A remote attacker can trigger this vulnerability via crafted input to execute arbitrary commands with root privileges. Exploitation requires valid administrative credentials for the device's web management interface.

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

The underlying weakness: Improper Neutralization of Special Elements used in an OS Command

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in VigorSwitch G2540xs

All VigorSwitch G2540xs vulnerabilities

Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities

Spotted an error? Tell us.