Improper Authentication Vulnerability in Totolink A8000R Router
CVE-2026-5676

6.9MEDIUM

Key Information:

Vendor

Totolink
Status
A8000r
Vendor
CVE Published:
6 April 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-5676?

A significant vulnerability exists in the Totolink A8000R router, particularly within the 'setLanguageCfg' function located in the /cgi-bin/cstecgi.cgi file. This weakness stems from the improper handling of the 'langType' argument, resulting in a lack of required authentication for certain operations. Attackers can exploit this flaw to gain unauthorized access and potentially execute arbitrary actions on the device. Given that this vulnerability can be triggered remotely and exploit code is publicly available, it heightens concerns for users of the affected firmware version.

Affected Version(s)

A8000R 5.9c.681_B20180413

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-2026-5676 - Proof of Concept

References

https://vuldb.com/vuln/355503
vdb-entrytechnical-description
https://vuldb.com/vuln/355503/cti
signaturepermissions-required
https://vuldb.com/submit/792433
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
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

skeet (VulDB User)
.