Stack-Based Buffer Overflow in D-Link DI-8400 DDNS Configuration
CVE-2026-91001

9.4CRITICAL

Key Information:

Vendor

D-link
Status
Di-8400
Vendor
CVE Published:
15 September 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-91001?

A security vulnerability has been identified in the D-Link DI-8400 router, specifically within the DDNS Configuration component. This vulnerability arises from a stack-based buffer overflow due to improper handling of the ddns_asp function located in the file /ddns.asp. A remote attacker can exploit this flaw by manipulating various input parameters, allowing for potentially harmful operations. The exploit code has been publicly released, emphasizing the urgency for users to secure their devices against such attacks. Users are advised to review their configurations and implement necessary security measures.

Affected Version(s)

DI-8400 16.07

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-91001 - Proof of Concept

References

https://vuldb.com/vuln/403582
vdb-entrytechnical-description
https://vuldb.com/vuln/403582/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-91001
third-party-advisory

CVSS V4

Score:
9.4
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Xray (VulDB User)
.