CVE-2026-19813: Stack-based Buffer Overflow in TOTOLINK A800R
A stack-based buffer overflow vulnerability exists in the TOTOLINK A800R firmware version 4.1.2cu.5137_B20200730, specifically in the setMacFilterRules function within /cgi-bin/cstecgi.cgi of the firewall.so component. This vulnerability can be exploited remotely by manipulating the Comment argument. The vulnerability has a high severity score of 8.8 and public exploit code has been disclosed, though no known exploits in the wild have been reported.
AI Analysis
Technical Summary
CVE-2026-19813 is a stack-based buffer overflow vulnerability affecting TOTOLINK A800R firmware 4.1.2cu.5137_B20200730. The flaw is in the setMacFilterRules function of /cgi-bin/cstecgi.cgi in the firewall.so component. An attacker with low privileges can remotely manipulate the Comment argument to trigger the overflow. The vulnerability has a CVSS 3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high impact on confidentiality, integrity, and availability. Public exploit code has been disclosed, but no active exploitation in the wild is currently known. No patch or remediation information is provided in the available data.
Potential Impact
Successful exploitation allows remote attackers with low privileges to cause a stack-based buffer overflow, potentially leading to arbitrary code execution or denial of service. The vulnerability impacts 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, restrict access to the vulnerable interface and monitor for suspicious activity related to the setMacFilterRules function. Avoid exposing the device's management interface to untrusted networks.
CVE-2026-19813: Stack-based Buffer Overflow in TOTOLINK A800R
Description
A stack-based buffer overflow vulnerability exists in the TOTOLINK A800R firmware version 4.1.2cu.5137_B20200730, specifically in the setMacFilterRules function within /cgi-bin/cstecgi.cgi of the firewall.so component. This vulnerability can be exploited remotely by manipulating the Comment argument. The vulnerability has a high severity score of 8.8 and public exploit code has been disclosed, though no known exploits in the wild have been reported.
CVSS v4.0
Score 8.7high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-19813 is a stack-based buffer overflow vulnerability affecting TOTOLINK A800R firmware 4.1.2cu.5137_B20200730. The flaw is in the setMacFilterRules function of /cgi-bin/cstecgi.cgi in the firewall.so component. An attacker with low privileges can remotely manipulate the Comment argument to trigger the overflow. The vulnerability has a CVSS 3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high impact on confidentiality, integrity, and availability. Public exploit code has been disclosed, but no active exploitation in the wild is currently known. No patch or remediation information is provided in the available data.
Potential Impact
Successful exploitation allows remote attackers with low privileges to cause a stack-based buffer overflow, potentially leading to arbitrary code execution or denial of service. The vulnerability impacts 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, restrict access to the vulnerable interface and monitor for suspicious activity related to the setMacFilterRules function. Avoid exposing the device's management interface to untrusted networks.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-4f74-rpch-f3gc
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-19813"]
- Ecosystems
- []
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a7f4405bf8831d5395fb334
Added to database: 08/14/2026, 16:36:21 UTC
Last enriched: 08/14/2026, 16:57:48 UTC
Last updated: 08/15/2026, 02:41:00 UTC
Views: 4
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