Buffer Overflow in TOTOLINK A800R Router Software
CVE-2026-19812

8.7HIGH

Key Information:

Vendor

Totolink
Status
A800r
Vendor
CVE Published:
14 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-19812?

A vulnerability has been found in the TOTOLINK A800R router version 4.1.2cu.5137_B20200730, specifically in the UploadCustomModule function located in the /cgi-bin/cstecgi.cgi file of the product.so component. This vulnerability allows an attacker to manipulate the File argument, potentially leading to a stack-based buffer overflow. Since the exploit can be executed remotely, this poses a significant risk to users. Publicly available exploits increase the urgency for organizations to secure their systems against potential attacks.

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-2026-19812 - Proof of Concept

References

https://vuldb.com/vuln/389948
vdb-entrytechnical-description
https://vuldb.com/vuln/389948/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-19812
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)
.