Executive brief
Netcore NR255-V is a wireless router used in home and small-office networks. A stack-based buffer overflow flaw in the reboot timer management interface allows authenticated attackers to corrupt router memory by submitting malformed input, potentially leading to code execution and complete device compromise.
Technical details
A stack-based buffer overflow (CWE-121) exists in the reboot_timer_set.cgi endpoint, caused by improper sscanf token parsing that fails to validate input length before writing to a fixed-size stack buffer. The vulnerability is network-accessible but requires authentication (administrator privileges) to trigger. An attacker with valid credentials can send crafted POST/GET requests to the vulnerable endpoint to overwrite the stack, potentially achieving arbitrary code execution on the router. A patch or firmware update from Netcore has not been announced as of the advisory publication date.
Affected products
- Netcore NR255-V 1.5.130703
Timeline
- 2026-09-15: disclosed: CVE-2026-76869 published
- 2026-08-19: other: Public research disclosure on GitHub