CVE-2026-19814: Stack-based Buffer Overflow in TOTOLINK A800R
CVE-2026-19814 is a stack-based buffer overflow vulnerability in the TOTOLINK A800R router firmware version 4.1.2cu.5137_B20200730. The flaw exists in the setMacQos function within the /cgi-bin/cstecgi.cgi file of the firewall.so component. An attacker can remotely exploit this vulnerability by manipulating the macAddress argument, potentially leading to code execution or denial of service. Exploit code is publicly available, increasing the risk of exploitation. No official patch or remediation guidance has been provided by the vendor as of the publication date.
AI Analysis
Technical Summary
This vulnerability affects TOTOLINK A800R firmware version 4.1.2cu.5137_B20200730. It is a stack-based buffer overflow in the setMacQos function of the /cgi-bin/cstecgi.cgi file within the firewall.so component. The vulnerability is triggered by manipulating the macAddress argument remotely, which can cause memory corruption. The vulnerability has a CVSS 4.0 base score of 8.7, indicating high severity. Exploit code is publicly available, but no official fix or patch has been disclosed by the vendor. The vulnerability allows unauthenticated remote attackers to potentially execute arbitrary code or cause a denial of service.
Potential Impact
Successful exploitation can lead to remote code execution or denial of service on the affected device. The vulnerability is remotely exploitable without user interaction and requires low attack complexity. The presence of public exploit code increases the likelihood of attacks. The vulnerability compromises the confidentiality, integrity, and availability of the affected device.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider limiting remote access to the affected device and monitoring for suspicious activity related to the setMacQos function. No vendor-provided mitigation or temporary fix is currently documented.
CVE-2026-19814: Stack-based Buffer Overflow in TOTOLINK A800R
Description
CVE-2026-19814 is a stack-based buffer overflow vulnerability in the TOTOLINK A800R router firmware version 4.1.2cu.5137_B20200730. The flaw exists in the setMacQos function within the /cgi-bin/cstecgi.cgi file of the firewall.so component. An attacker can remotely exploit this vulnerability by manipulating the macAddress argument, potentially leading to code execution or denial of service. Exploit code is publicly available, increasing the risk of exploitation. No official patch or remediation guidance has been provided by the vendor as of the publication date.
CVSS v4.0
Score 8.7high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability affects TOTOLINK A800R firmware version 4.1.2cu.5137_B20200730. It is a stack-based buffer overflow in the setMacQos function of the /cgi-bin/cstecgi.cgi file within the firewall.so component. The vulnerability is triggered by manipulating the macAddress argument remotely, which can cause memory corruption. The vulnerability has a CVSS 4.0 base score of 8.7, indicating high severity. Exploit code is publicly available, but no official fix or patch has been disclosed by the vendor. The vulnerability allows unauthenticated remote attackers to potentially execute arbitrary code or cause a denial of service.
Potential Impact
Successful exploitation can lead to remote code execution or denial of service on the affected device. The vulnerability is remotely exploitable without user interaction and requires low attack complexity. The presence of public exploit code increases the likelihood of attacks. The vulnerability compromises the confidentiality, integrity, and availability of the affected device.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider limiting remote access to the affected device and monitoring for suspicious activity related to the setMacQos function. No vendor-provided mitigation or temporary fix is currently documented.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulDB
- Date Reserved
- 2026-08-14T00:55:47.227Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a7ed848bf8831d539bd719b
Added to database: 08/14/2026, 08:56:40 UTC
Last enriched: 08/21/2026, 14:02:49 UTC
Last updated: 09/07/2026, 10:52:07 UTC
Views: 58
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.