Buffer Overflow Vulnerability in Tenda AC21 by Tenda
CVE-2026-4565

8.7HIGH

Key Information:

Vendor

Tenda
Status
Ac21
Vendor
CVE Published:
23 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-4565?

A buffer overflow vulnerability in Tenda AC21 affects the formSetQosBand function in the /goform/SetNetControlList file. This security issue can be triggered by manipulating the argument list, allowing remote attackers to exploit the vulnerability. The potential for exploitation is now public, raising concerns for users regarding their network security and device stability.

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Affected Version(s)

AC21 16.03.08.16

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-2026-4565 - Proof of Concept

References

https://vuldb.com/?id.352402
vdb-entrytechnical-description
https://vuldb.com/?ctiid.352402
signaturepermissions-required
https://vuldb.com/?submit.775119
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

junqi (VulDB User)
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