What is CVE-2026-71920?

CVE-2026-71920 is a medium-severity vulnerability, classified under NULL Pointer Dereference. CVSS score: 4.9/10. Published 2026-08-24.

How severe is CVE-2026-71920?

Medium severity. CVSS v3 base score is 4.9 out of 10.

CVE-2026-71920

CVE-2026-71920

Multiple DrayTek VigorSwitch models contain a null pointer dereference vulnerability in the formlogout function. The vulnerability is caused by missing checks for an empty or absent Cookie header before string handling. A remote attacker can trigger this vulnerability via a crafted request to crash the service and cause a denial of service. Exploitation requires valid administrative credentials for the device's web management interface.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-71920?: CVE-2026-71920 is a medium-severity vulnerability, classified under NULL Pointer Dereference. CVSS score: 4.9/10. Published 2026-08-24.
How severe is CVE-2026-71920?: Medium severity. CVSS v3 base score is 4.9 out of 10.