Vulnerability · Published Aug 14, 2026 · Assigned by VulDB

CVE-2026-19813TOTOLINK A800R firewall.so cstecgi.cgi setMacFilterRules stack-based overflow

High 8.8

In plain English

A high-severity stack buffer overflow in A800R from TOTOLINK. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 58% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.9%top 41.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

A security vulnerability has been detected in TOTOLINK A800R 4.1.2cu.5137_B20200730. This impacts the function setMacFilterRules of the file /cgi-bin/cstecgi.cgi of the component firewall.so. Such manipulation of the argument Comment leads to stack-based buffer overflow. The attack may be performed from remote. The exploit has been disclosed publicly and may be used.

Affected products (as reported)

Vendor	Product	Versions
TOTOLINK	A800R	4.1.2cu.5137_B20200730

Weakness: CWE-121, CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R

References

VDB-389949 | TOTOLINK A800R firewall.so cstecgi.cgi setMacFilterRules stack-based overflow vdb-entry, technical-description
VDB-389949 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
CVE-2026-19813 | CVE Analysis and Report third-party-advisory
Submit #869430 | Totolink A800R V4.1.2cu.5137_B20200730 Buffer Overflow third-party-advisory
https://github.com/panda666-888/vuls/blob/main/totolink/a800r/setMacFilterRules.md exploit
https://www.totolink.net/ product