Threat Investigation
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CVE-2026-71940

High

Description

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the acl_general_setup Edit ACE function. The vulnerability is caused by copying the name field into a fixed-size buffer without length validation. A remote attacker can trigger this vulnerability via crafted input, causing a denial of service or potentially executing arbitrary commands. Exploitation requires valid administrative credentials for the device's web management interface.

SeverityHigh
CVSS7.2
Exploit probability—
ProductVigorSwitch G2540xs
PublishedAug 24, 2026
First seenAug 24, 2026
Weakness typeCWE-120CWE-120

How to fix

Update
  • DrayTek Corporation VigorSwitch G2540xs3.9.10 or later
  • DrayTek Corporation VigorSwitch P2540xs3.9.10 or later
  • DrayTek Corporation VigorSwitch FX21203.9.10 or later
  • DrayTek Corporation VigorSwitch G2282x2.10.6 or later
  • DrayTek Corporation VigorSwitch P2282x2.10.6 or later
  • DrayTek Corporation VigorSwitch Q2300x2.10.7 or later
  • DrayTek Corporation VigorSwitch PQ2300xb2.10.7 or later
  • DrayTek Corporation VigorSwitch G2542x3.10.6 or later
  • DrayTek Corporation VigorSwitch P2542x3.10.6 or later
  • DrayTek Corporation VigorSwitch P2542xh3.10.6 or later
  • DrayTek Corporation VigorSwitch PX20602.9.10 or later
  • DrayTek Corporation VigorSwitch G12802.9.10 or later
Vendor advisories

Affected products

ProductAffected versionsFixed in
DrayTek Corporation VigorSwitch G2540xsv < 3.9.103.9.10
DrayTek Corporation VigorSwitch P2540xsv < 3.9.103.9.10
DrayTek Corporation VigorSwitch FX2120v < 3.9.103.9.10
DrayTek Corporation VigorSwitch G2282xv < 2.10.62.10.6
DrayTek Corporation VigorSwitch P2282xv < 2.10.62.10.6
DrayTek Corporation VigorSwitch Q2300xv < 2.10.72.10.7
DrayTek Corporation VigorSwitch PQ2300xbv < 2.10.72.10.7
DrayTek Corporation VigorSwitch G2542xv < 3.10.63.10.6
DrayTek Corporation VigorSwitch P2542xv < 3.10.63.10.6
DrayTek Corporation VigorSwitch P2542xhv < 3.10.63.10.6
DrayTek Corporation VigorSwitch PX2060v < 2.9.102.9.10
DrayTek Corporation VigorSwitch G1280v < 2.9.102.9.10
DrayTek Corporation VigorSwitch P1280v < 2.9.102.9.10
DrayTek Corporation VigorSwitch P1281xv < 2.9.102.9.10
DrayTek Corporation VigorSwitch G1282v < 2.9.102.9.10
DrayTek Corporation VigorSwitch P1282v < 2.9.102.9.10
DrayTek Corporation VigorSwitch G2121v < 2.9.102.9.10
DrayTek Corporation VigorSwitch P2121v < 2.9.102.9.10
DrayTek Corporation VigorSwitch PQ2121xv < 2.9.102.9.10
DrayTek Corporation VigorSwitch Q2121xv < 2.9.102.9.10
DrayTek Corporation VigorSwitch G2280xv < 2.9.102.9.10
DrayTek Corporation VigorSwitch P2280xv < 2.9.102.9.10
DrayTek Corporation VigorSwitch Q2200xv < 2.9.102.9.10
DrayTek Corporation VigorSwitch PQ2200xbv < 2.9.102.9.10
DrayTek Corporation VigorSwitch G2100v < 2.9.102.9.10
DrayTek Corporation VigorSwitch P2100v < 2.9.102.9.10
DrayTek Corporation VigorSwitch G2540xv < 2.9.102.9.10
DrayTek Corporation VigorSwitch P2540xv < 2.9.102.9.10

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