CVE-2026-71927: DrayTek VigorSwitch command injection in rebDevice

CVE-2026-71927 · Severity: high · CVSS 7.2 · Published 2026-08-24

DrayTek VigorSwitch is a managed network switch used to segment and control corporate network traffic. A command injection vulnerability in the device's web management interface allows authenticated administrators to execute arbitrary system commands with root-level privileges by submitting malicious input in username and password fields, potentially enabling full system compromise and lateral movement within the network.

Technologies: DrayTek VigorSwitch FX2120, DrayTek VigorSwitch G1280, DrayTek VigorSwitch G1282, DrayTek VigorSwitch G2100, DrayTek VigorSwitch G2121, DrayTek VigorSwitch G2280x, DrayTek VigorSwitch G2282x, DrayTek VigorSwitch G2540x, DrayTek VigorSwitch G2540xs, DrayTek VigorSwitch G2542x, DrayTek VigorSwitch P1280, DrayTek VigorSwitch P1281x, DrayTek VigorSwitch P1282, DrayTek VigorSwitch P2100, DrayTek VigorSwitch P2121, DrayTek VigorSwitch P2280x, DrayTek VigorSwitch P2282x, DrayTek VigorSwitch P2540x, DrayTek VigorSwitch P2540xs, DrayTek VigorSwitch P2542x, DrayTek VigorSwitch P2542xh, DrayTek VigorSwitch PQ2121x, DrayTek VigorSwitch PQ2200xb, DrayTek VigorSwitch PQ2300xb, DrayTek VigorSwitch PX2060, DrayTek VigorSwitch Q2121x, DrayTek VigorSwitch Q2200x, DrayTek VigorSwitch Q2300x. Vendors: DrayTek.

Quick answers

Is CVE-2026-71927 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-71927 being exploited in the wild.
How severe is CVE-2026-71927?
High severity, with a CVSS score of 7.2, published 24 August 2026.
Which products and versions are affected?
DrayTek VigorSwitch FX2120 < 3.9.10; DrayTek VigorSwitch G1280 < 2.9.10; DrayTek VigorSwitch G1282 < 2.9.10; DrayTek VigorSwitch G2100 < 2.9.10; and 24 more.
Is there a fix for CVE-2026-71927?
A patch was published on 2026-08-24: Fixed firmware versions released for all affected VigorSwitch models Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-71927 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-71927?
Check whether you run DrayTek VigorSwitch FX2120, DrayTek VigorSwitch G1280, DrayTek VigorSwitch G1282 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a classic OS command injection (CWE-78) in the rebDevice function within the mainfunction.cgi component of VigorSwitch firmware. The root cause is insufficient input validation and filtering of the username and password fields before they are passed to a command execution context. Attack vector is network-based via the device's web management interface; however, exploitation requires valid administrative credentials—reducing the attack surface to authenticated insiders or attackers with compromised admin accounts. A successful exploit allows arbitrary command execution with root privileges on the affected appliance. Patches are available in fixed firmware versions released August 2026 for all affected VigorSwitch models.

Affected products

  • DrayTek VigorSwitch G2540xs < 3.9.10
  • DrayTek VigorSwitch P2540xs < 3.9.10
  • DrayTek VigorSwitch FX2120 < 3.9.10
  • DrayTek VigorSwitch G2282x < 2.10.6
  • DrayTek VigorSwitch P2282x < 2.10.6
  • DrayTek VigorSwitch Q2300x < 2.10.7
  • DrayTek VigorSwitch PQ2300xb < 2.10.7
  • DrayTek VigorSwitch G2542x < 3.10.6
  • DrayTek VigorSwitch P2542x < 3.10.6
  • DrayTek VigorSwitch P2542xh < 3.10.6
  • DrayTek VigorSwitch PX2060 < 2.9.10
  • DrayTek VigorSwitch G1280 < 2.9.10
  • DrayTek VigorSwitch P1280 < 2.9.10
  • DrayTek VigorSwitch P1281x < 2.9.10
  • DrayTek VigorSwitch G1282 < 2.9.10
  • DrayTek VigorSwitch P1282 < 2.9.10
  • DrayTek VigorSwitch G2121 < 2.9.10
  • DrayTek VigorSwitch P2121 < 2.9.10
  • DrayTek VigorSwitch PQ2121x < 2.9.10
  • DrayTek VigorSwitch Q2121x < 2.9.10
  • DrayTek VigorSwitch G2280x < 2.9.10
  • DrayTek VigorSwitch P2280x < 2.9.10
  • DrayTek VigorSwitch Q2200x < 2.9.10
  • DrayTek VigorSwitch PQ2200xb < 2.9.10
  • DrayTek VigorSwitch G2100 < 2.9.10
  • DrayTek VigorSwitch P2100 < 2.9.10
  • DrayTek VigorSwitch G2540x < 2.9.10
  • DrayTek VigorSwitch P2540x < 2.9.10

Timeline

  • 2026-08-24: disclosed: DrayTek security advisory DSA-2026-003 published
  • 2026-08-24: patched: Fixed firmware versions released for all affected VigorSwitch models

References

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