Buffer overflow in Tenda A21
CVE-2026-2870
A security flaw has been discovered in Tenda A21 1.0.0.0. Affected by this issue is the function set_qosMib_list of the file /goform/formSetQosBand. The manipulation of the argument list results in stack-based buffer overflow. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks.
Vulnerability class: Buffer Overflow
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.010 (62.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 62.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.010 · change: +0.004
Affected products
- Tenda A21 — versions 1.0.0.0
- Tenda A21 Firmware — versions 1.0.0.0
Weakness classification (CWE)
References
- vuldb.com/ (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
- vuldb.com/ (signature, Permissions Required, permissions-required, VDB Entry)
- vuldb.com/ (VDB Entry, Third Party Advisory, third-party-advisory)
- github.com/QIU-DIE/cve-nneeww/issues/1 (issue-tracking, Exploit, Third Party Advisory, exploit, Mitigation, Issue Tracking)
- www.tenda.com.cn/ (Product, product)
Frequently asked questions
- What is CVE-2026-2870?
- CVE-2026-2870 is a high-severity vulnerability in Tenda A21, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.8/10. Published 2026-02-21.
- How severe is CVE-2026-2870?
- High severity. CVSS v3 base score is 8.8 out of 10.