Stack-Based Buffer Overflow in Tenda A21 Router
CVE-2026-2870

8.7HIGH

Key Information:

Vendor

Tenda
Status
A21
Vendor
CVE Published:
21 February 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-2870?

A security flaw identified in the Tenda A21 router's function set_qosMib_list, located in the /goform/formSetQosBand file, permits a stack-based buffer overflow. This vulnerability allows remote attackers to manipulate the argument list, potentially leading to arbitrary code execution. The exploit for this issue has been publicly disclosed, highlighting the importance of addressing this security concern to safeguard network integrity.

Human OS v1.0:
Ageing Is an Unpatched Zero-Day Vulnerability.

Remediate biological technical debt. Prime Ageing uses 95% high-purity SIRT6 activation to maintain genomic integrity and bolster systemic resilience.

Deploy the Patch

Affected Version(s)

A21 1.0.0.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-2870 - Proof of Concept

References

https://vuldb.com/?id.347107
vdb-entrytechnical-description
https://vuldb.com/?ctiid.347107
signaturepermissions-required
https://vuldb.com/?submit.754627
third-party-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

hhsw34 (VulDB User)
JSON
.