CVE-2026-19812 TOTOLINK A800R product.so cstecgi.cgi UploadCustomModule stack-based overflow
Remote attackers can trigger a stack-based buffer overflow in the TOTOLINK A800R router via the UploadCustomModule function, potentially leading to 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-2026-19812?
CVE-2026-19812 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 weakness has been identified in TOTOLINK A800R 4.1.2cu.5137_B20200730. This affects the function UploadCustomModule of the file /cgi-bin/cstecgi.cgi of the component product.so. This manipulation of the argument File causes stack-based buffer overflow. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks.
Which versions are affected by CVE-2026-19812?
How do I fix CVE-2026-19812?
No fix has been published for CVE-2026-19812 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-2026-19812 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-19812 exists.
Sources
Also known as GHSA-8w2r-9wr9-7g8j.