DrayTek VigorSwitch G2540xs Ping Trace pingtrace host/count/interval buffer overflow

Summaryinfo

A vulnerability identified as very critical has been detected in DrayTek VigorSwitch G2540xs, VigorSwitch P2540xs, VigorSwitch FX2120, VigorSwitch G2282x, VigorSwitch P2282x, VigorSwitch Q2300x, VigorSwitch PQ2300xb, VigorSwitch G2542x, VigorSwitch P2542x, VigorSwitch P2542xh, VigorSwitch PX2060, VigorSwitch G1280, VigorSwitch P1280, VigorSwitch P1281x, VigorSwitch G1282, VigorSwitch P1282, VigorSwitch G2121, VigorSwitch P2121, VigorSwitch PQ2121x, VigorSwitch Q2121x, VigorSwitch G2280x, VigorSwitch P2280x, VigorSwitch Q2200x, VigorSwitch PQ2200xb, VigorSwitch G2100, VigorSwitch P2100, VigorSwitch G2540x and VigorSwitch P2540x. Affected is the function pingtrace of the component Ping Trace. Performing a manipulation of the argument host/count/interval results in buffer overflow. This vulnerability is reported as CVE-2026-71934. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability classified as very critical has been found in DrayTek VigorSwitch G2540xs, VigorSwitch P2540xs, VigorSwitch FX2120, VigorSwitch G2282x, VigorSwitch P2282x, VigorSwitch Q2300x, VigorSwitch PQ2300xb, VigorSwitch G2542x, VigorSwitch P2542x, VigorSwitch P2542xh, VigorSwitch PX2060, VigorSwitch G1280, VigorSwitch P1280, VigorSwitch P1281x, VigorSwitch G1282, VigorSwitch P1282, VigorSwitch G2121, VigorSwitch P2121, VigorSwitch PQ2121x, VigorSwitch Q2121x, VigorSwitch G2280x, VigorSwitch P2280x, VigorSwitch Q2200x, VigorSwitch PQ2200xb, VigorSwitch G2100, VigorSwitch P2100, VigorSwitch G2540x and VigorSwitch P2540x. This affects the function pingtrace of the component Ping Trace. The manipulation of the argument host/count/interval with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the pingtrace function. The vulnerability is caused by missing length checks when the host, count, and interval fields are concatenated 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.

It is possible to read the advisory at draytek.com. This vulnerability is uniquely identified as CVE-2026-71934 since 08/08/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Additional levels of successful authentication are required for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/24/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-64993). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• DrayTek

Name

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

License

• commercial

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

Discussion