Buffer Overflow Vulnerability in Tenda AC5 Router
CVE-2026-4903

8.7HIGH

Key Information:

Vendor

Tenda
Status
Ac5
Vendor
CVE Published:
26 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-4903?

A vulnerability in the Tenda AC5 router, specifically in version 15.03.06.47, allows for a stack-based buffer overflow via the formQuickIndex function of the /goform/QuickIndex component. This issue arises from improper handling of the PPPOEPassword argument in POST requests, which can be exploited remotely to execute arbitrary code or disrupt service. The exploit has been made public, highlighting the urgent need for users to evaluate their security posture and apply necessary patches.

Affected Version(s)

AC5 15.03.06.47

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-2026-4903 - Proof of Concept

References

https://vuldb.com/?id.353654
vdb-entrytechnical-description
https://vuldb.com/?ctiid.353654
signaturepermissions-required
https://vuldb.com/?submit.777380
third-party-advisory

EPSS Score

5% chance of being exploited in the next 30 days.

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

wxhwxhwxh_mie (VulDB User)
.