Executive brief
A security vulnerability exists in the D-Link DI-8100 router, a device used to manage internet connectivity for small businesses and homes. An attacker with administrative access can send a specially crafted request to the router's management interface to cause a system crash or potentially take full control of the device. This could lead to a total loss of internet availability or allow an attacker to intercept network traffic.
Technical details
A stack-based buffer overflow (CWE-121) exists in the D-Link DI-8100 firmware version 16.07.26A1. The vulnerability is located within the Web Management Interface in the /url_member.asp component. An authenticated attacker can trigger the overflow by supplying an excessively long string to the 'Name' argument during an 'add' operation. Because the application copies this input into a fixed-size stack buffer without adequate length validation, it results in memory corruption. This can be leveraged to cause a process crash (Denial of Service) or potentially achieve Remote Code Execution (RCE). While the attack is reachable over the network, it requires high privileges (administrative authentication).
Affected products
- D-Link DI-8100 16.07.26A1
Timeline
- 2026-05-05: disclosed: Initial disclosure and publication of CVE-2026-7856
- 2026-05-05: advisory