Junglewise Threat Intelligence

CVE-2026-91001: D-Link DI-8400 stack buffer overflow in DDNS configuration

CVE-2026-91001 · Severity: critical · CVSS 9.9 · Published 2026-09-15

Executive brief

D-Link DI-8400 is a network appliance with a Dynamic DNS (DDNS) configuration feature that allows remote management of domain names. A remote attacker with network access can trigger a stack-based buffer overflow by sending maliciously crafted DDNS parameters, potentially leading to device crash, data corruption, or arbitrary code execution.

Technical details

The vulnerability is a stack-based buffer overflow in the ddns_asp function within the /ddns.asp component of D-Link DI-8400 firmware version 16.07. The vulnerability exists due to insufficient input validation on DDNS configuration parameters (serv, user, host, wild, mx, bmx, cust, ip). An attacker can send oversized or maliciously crafted input via HTTP POST requests to exceed the buffer boundary and overwrite the stack return address. The attack requires network access to the device's web interface and valid authentication credentials (as evidenced by the cookie-based authentication in exploit code). A public exploit demonstrating the crash has been released. Affected versions: D-Link DI-8400 16.07.

Affected products

  • D-Link DI-8400 16.07

Timeline

  • 2026-09-15: disclosed
  • other: Public exploit code released on GitHub

References

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