Description
Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the sysreboot function. The vulnerability is caused by unsafe concatenation of split valueN data into a fixed-size buffer. 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.
Published: 2026-08-24
Score: 8.6 High
EPSS: < 1% Very Low
KEV: No
Impact: Remote Code Execution
Action: Immediate Patch
AI Analysis

Impact

The vulnerability is a buffer overflow in the sysreboot function caused by unsafe concatenation of split valueN data into a fixed-size buffer. A remote attacker with valid administrative credentials can trigger the vulnerability via crafted input through the device's web management interface, leading to a denial of service or potentially executing arbitrary commands. The weakness is classified as CWE-120.

Affected Systems

Affected systems include a broad range of DrayTek VigorSwitch models: FX2120, G1280, G1282, G2100, G2121, G2280x, G2282x, G2540x, G2540xs, G2542x, P1280, P1281x, P1282, P2100, P2121, P2280x, P2282x, P2540x, P2540xs, P2542x, P2542xh, PQ2121x, PQ2200xb, PQ2300xb, PX2060, Q2121x, Q2200x, and Q2300x. All models run the affected firmware versions referenced in the advisory.

Risk and Exploitability

The CVSS score of 8.6 categorizes this flaw as high severity. EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog. Exploitation requires authenticated access to the web management interface, making the risk significant for environments where credentials are known or weak. Once authenticated, an attacker can deliver malicious payloads that trigger the buffer overflow, potentially gaining arbitrary command execution on the device. Therefore, the likelihood of exploitation is elevated in enterprises with remote or locally accessed management interfaces that are not properly secured.

Generated by OpenCVE AI on August 24, 2026 at 19:15 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update the device firmware to the latest version that addresses the sysreboot buffer overflow per the DrayTek advisory.
  • If a patch is not yet available, restrict the web management interface to a trusted network segment or IP whitelisting, and block all unauthenticated access from external networks.
  • Change the default or previously used administrative credentials to strong, unique passwords and consider disabling remote web access if not needed.
  • Monitor device logs for abnormal reboot attempts or memory corruption indicators and investigate any suspicious activity promptly.

Generated by OpenCVE AI on August 24, 2026 at 19:15 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Thu, 27 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 24 Aug 2026 17:30:00 +0000

Type Values Removed Values Added
Description Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the sysreboot function. The vulnerability is caused by unsafe concatenation of split valueN data into a fixed-size buffer. 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.
Title DrayTek VigorSwitch Multiple Models Buffer Overflow via sysreboot
First Time appeared Draytek
Draytek vigorswitch Fx2120 Firmware
Draytek vigorswitch G1282 Firmware
Draytek vigorswitch G2100 Firmware
Draytek vigorswitch G2121 Firmware
Draytek vigorswitch G2280x Firmware
Draytek vigorswitch G2540xs Firmware
Draytek vigorswitch P1282 Firmware
Draytek vigorswitch P2100 Firmware
Draytek vigorswitch P2280x Firmware
Draytek vigorswitch P2540xs Firmware
Draytek vigorswitch Pq2121x Firmware
Draytek vigorswitch Pq2200xb Firmware
Draytek vigorswitch Q2121x Firmware
Draytek vigorswitch Q2200x Firmware
Weaknesses CWE-120
CPEs cpe:2.3:o:draytek:vigorswitch_fx2120_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_g1282_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_g2100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_g2121_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_g2280x_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_g2540xs_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_p1282_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_p2100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_p2280x_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_p2540xs_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_pq2121x_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_pq2200xb_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_q2121x_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:draytek:vigorswitch_q2200x_firmware:*:*:*:*:*:*:*:*
Vendors & Products Draytek
Draytek vigorswitch Fx2120 Firmware
Draytek vigorswitch G1282 Firmware
Draytek vigorswitch G2100 Firmware
Draytek vigorswitch G2121 Firmware
Draytek vigorswitch G2280x Firmware
Draytek vigorswitch G2540xs Firmware
Draytek vigorswitch P1282 Firmware
Draytek vigorswitch P2100 Firmware
Draytek vigorswitch P2280x Firmware
Draytek vigorswitch P2540xs Firmware
Draytek vigorswitch Pq2121x Firmware
Draytek vigorswitch Pq2200xb Firmware
Draytek vigorswitch Q2121x Firmware
Draytek vigorswitch Q2200x Firmware
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Subscriptions

Draytek Vigorswitch Fx2120 Firmware Vigorswitch G1282 Firmware Vigorswitch G2100 Firmware Vigorswitch G2121 Firmware Vigorswitch G2280x Firmware Vigorswitch G2540xs Firmware Vigorswitch P1282 Firmware Vigorswitch P2100 Firmware Vigorswitch P2280x Firmware Vigorswitch P2540xs Firmware Vigorswitch Pq2121x Firmware Vigorswitch Pq2200xb Firmware Vigorswitch Q2121x Firmware Vigorswitch Q2200x Firmware
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-27T13:52:16.469Z

Reserved: 2026-08-08T16:37:44.519Z

Link: CVE-2026-71936

cve-icon Vulnrichment

Updated: 2026-08-27T13:52:10.490Z

cve-icon NVD

Status : Deferred

Published: 2026-08-24T18:17:18.693

Modified: 2026-08-27T17:19:49.213

Link: CVE-2026-71936

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-24T19:30:17Z

Weaknesses
  • CWE-120

    Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')