Buffer overflow in Tenda Ac21
CVE-2026-4565
A vulnerability was detected in Tenda AC21 16.03.08.16. Impacted is the function formSetQosBand of the file /goform/SetNetControlList. Performing a manipulation of the argument list results in buffer overflow. The attack can be initiated r…
Vulnerability class: Buffer Overflow
EPSS: 0.001 (27.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R.
Affected products
- Tenda Ac21 — versions 16.03.08.16
Weakness classification (CWE)
References
- VDB-352402 | Tenda AC21 SetNetControlList formSetQosBand buffer overflow (vdb-entry, technical-description)
- VDB-352402 | CTI Indicators (IOB, IOC, IOA) (signature, permissions-required)
- Submit #775119 | Tenda AC21 Tenda AC21 V1.0 V16.03.08.16 Buffer Overflow (third-party-advisory)
- github.com/hellonestor/killallbug/issues/14 (issue-tracking)
- github.com/hellonestor/killallbug/releases/tag/poc (exploit, patch)
- www.tenda.com.cn/ (product)
Frequently asked questions
- What is CVE-2026-4565?
- CVE-2026-4565 is a high-severity vulnerability in Tenda Ac21, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 8.8/10. Published 2026-03-23.
- How severe is CVE-2026-4565?
- High severity. CVSS v3 base score is 8.8 out of 10.