Buffer Overflow Vulnerability in DrayTek VigorSwitch Models
CVE-2026-71938

8.6HIGH

Key Information:

Vendor

Draytek Corporation

Status
Vigorswitch G2540xs
Vigorswitch P2540xs
Vigorswitch Fx2120
Vigorswitch G2282x
Vendor
CVE Published:
24 August 2026

What is CVE-2026-71938?

Multiple models of DrayTek VigorSwitch are susceptible to a buffer overflow vulnerability in the switch_lan_gvrp function. This issue arises from unsafe practices in copying data into a smaller buffer than required, potentially leading to denial of service conditions. A remote attacker with valid administrative credentials might exploit this vulnerability through specially crafted input, risking the execution of arbitrary commands or service disruption on affected devices. Immediate actions are recommended to secure the management interface and mitigate risks.

Affected Version(s)

VigorSwitch FX2120 0 < 3.9.10

VigorSwitch G1280 0 < 2.9.10

VigorSwitch G1282 0 < 2.9.10

References

https://www.draytek.com/about/security-advisory/multiple-...
vendor-advisory
https://www.vulncheck.com/advisories/draytek-vigorswitch-...
third-party-advisory

CVSS V4

Score:
8.6
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Jincheng Wang (@winmt)
Le Yu (Nanjing University of Posts and Telecommunications)
Xiapu Luo (The Hong Kong Polytechnic University)
.