Buffer Overflow Vulnerability in TOTOLINK A800R Firewall Component
CVE-2026-19813

8.7HIGH

Key Information:

Vendor

Totolink
Status
A800r
Vendor
CVE Published:
14 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-19813?

A vulnerability has been identified in the TOTOLINK A800R router, specifically within the firewall component's setMacFilterRules function. This issue arises due to improper handling of the Comment argument in the /cgi-bin/cstecgi.cgi file, leading to a stack-based buffer overflow condition. Attackers could leverage this flaw to execute malicious code remotely, potentially compromising the integrity and security of affected devices. Public disclosure of this vulnerability raises concerns for users who have not yet applied security updates.

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-2026-19813 - Proof of Concept

References

https://vuldb.com/vuln/389949
vdb-entrytechnical-description
https://vuldb.com/vuln/389949/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-19813
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)
.