CVE-2026-19813 TOTOLINK A800R firewall.so cstecgi.cgi setMacFilterRules stack-based overflow
Remote attackers can trigger a stack-based buffer overflow in the firewall component via the setMacFilterRules function, potentially leading to arbitrary code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-19813?
CVE-2026-19813 is a high-severity memory corruption vulnerability in TOTOLINK A800R, published on 14 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Which versions are affected by CVE-2026-19813?
How do I fix CVE-2026-19813?
No fix has been published for CVE-2026-19813 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-19813 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-19813 exists.
Sources
Also known as GHSA-4f74-rpch-f3gc.