CVE-2026-19813: totolink a800r_firmware

Vulnerability summary

CVE-2026-19813 is a high (CVSS 9.0) vulnerability in totolink a800r_firmware. EPSS estimates a 0.85% chance of exploitation in the next 30 days, higher than 57.8% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 14-08-2026
   PublishedVulnerability first disclosed.
2. 18-08-2026
   Last modifiedVulnerability information updated.

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.

• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).