Buffer Overflow in TOTOLINK A800R Firewall Component
CVE-2026-19846

8.7HIGH

Key Information:

Vendor

Totolink
Status
A800r
Vendor
CVE Published:
14 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-19846?

A stack-based buffer overflow vulnerability exists in the setUrlFilterRules function of the firewall component in the TOTOLINK A800R router. This vulnerability can be exploited remotely by manipulating the url parameter in the /cgi-bin/cstecgi.cgi file. If successfully executed, it may lead to unauthorized access and control over the device. Publicly available exploits increase the risk of this vulnerability being exploited in the wild.

Affected Version(s)

A800R 4.1.2cu.5137_B20200730

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-2026-19846 - Proof of Concept

References

https://vuldb.com/vuln/389982
vdb-entrytechnical-description
https://vuldb.com/vuln/389982/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-19846
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

panda_0x1 (VulDB User)
.