CVE-2026-19812: Stack-based Buffer Overflow in TOTOLINK A800R
CVE-2026-19812 is a stack-based buffer overflow vulnerability in the TOTOLINK A800R router firmware version 4.1.2cu.5137_B20200730. The flaw exists in the UploadCustomModule function of the /cgi-bin/cstecgi.cgi file within the product.so component. This vulnerability can be exploited remotely by manipulating the File argument, potentially leading to severe impacts. Public exploit code is available, increasing the risk of attack. No official patch or remediation guidance has been provided by the vendor at this time.
AI Analysis
Technical Summary
The vulnerability CVE-2026-19812 affects TOTOLINK A800R firmware version 4.1.2cu.5137_B20200730. It is a stack-based buffer overflow in the UploadCustomModule function of the /cgi-bin/cstecgi.cgi CGI script, specifically in the product.so component. The vulnerability is triggered by manipulating the File argument, allowing remote attackers to cause a buffer overflow on the stack. This can lead to potential code execution or denial of service. Exploit code has been publicly released, but no vendor remediation or patch has been announced yet.
Potential Impact
Successful exploitation of this vulnerability could allow remote attackers to execute arbitrary code or cause a denial of service on the affected device. Given the high CVSS score of 8.7 and the availability of public exploit code, the risk of exploitation is significant. The vulnerability requires no user interaction and has low attack complexity, increasing its threat level.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider limiting exposure of the affected device to untrusted networks and monitor for unusual activity. No official vendor mitigation or workaround has been provided.
CVE-2026-19812: Stack-based Buffer Overflow in TOTOLINK A800R
Description
CVE-2026-19812 is a stack-based buffer overflow vulnerability in the TOTOLINK A800R router firmware version 4.1.2cu.5137_B20200730. The flaw exists in the UploadCustomModule function of the /cgi-bin/cstecgi.cgi file within the product.so component. This vulnerability can be exploited remotely by manipulating the File argument, potentially leading to severe impacts. Public exploit code is available, increasing the risk of attack. No official patch or remediation guidance has been provided by the vendor at this time.
CVSS v4.0
Score 8.7high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-19812 affects TOTOLINK A800R firmware version 4.1.2cu.5137_B20200730. It is a stack-based buffer overflow in the UploadCustomModule function of the /cgi-bin/cstecgi.cgi CGI script, specifically in the product.so component. The vulnerability is triggered by manipulating the File argument, allowing remote attackers to cause a buffer overflow on the stack. This can lead to potential code execution or denial of service. Exploit code has been publicly released, but no vendor remediation or patch has been announced yet.
Potential Impact
Successful exploitation of this vulnerability could allow remote attackers to execute arbitrary code or cause a denial of service on the affected device. Given the high CVSS score of 8.7 and the availability of public exploit code, the risk of exploitation is significant. The vulnerability requires no user interaction and has low attack complexity, increasing its threat level.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider limiting exposure of the affected device to untrusted networks and monitor for unusual activity. No official vendor mitigation or workaround has been provided.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulDB
- Date Reserved
- 2026-08-14T00:55:39.511Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a7eca46bf8831d539a9f996
Added to database: 08/14/2026, 07:56:54 UTC
Last enriched: 08/14/2026, 08:11:06 UTC
Last updated: 08/14/2026, 08:27:05 UTC
Views: 5
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