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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.006 (44.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Weakness classification (CWE)
References
- www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch… (vendor-advisory)
- www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-null-pointer-d… (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.