What is the CVSS score of CVE-2026-3678?

CVE-2026-3678 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Fh451 Firmware are affected by CVE-2026-3678?

A high-severity vulnerability (CVSS 8.8) affects Tenda FH451 routers with no patch currently available, creating immediate risk for organizations relying on these devices for network connectivity.

Is there a public PoC exploit available for CVE-2026-3678?

Yes, a public proof-of-concept exploit is available for CVE-2026-3678. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-3678?

Within 24 hours: Inventory all Tenda FH451 1.0.0.9 devices in your environment and isolate affected units from production networks if possible. Within 7 days: Implement network segmentation to restrict administrative access to these devices and enable enhanced logging on network perimeter devices. Within 30 days: Develop a replacement strategy with vendors and plan device migration to alternative manufacturers with active security support.

Fh451 Firmware CVE-2026-3678

HIGH

Buffer Overflow (CWE-119)

2026-03-07 cna@vuldb.com

Buffer Overflow Stack Overflow Fh451 Firmware

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

PoC Detected

Mar 09, 2026 - 16:16 vuln.today

Public exploit code

CVE Published

Mar 07, 2026 - 23:15 nvd

HIGH 8.8

DescriptionCVE.org

A vulnerability was determined in Tenda FH451 1.0.0.9. Affected is the function sub_3C434 of the file /goform/AdvSetWan. This manipulation of the argument wanmode/PPPOEPassword causes stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been publicly disclosed and may be utilized.

AnalysisAI

Remote code execution in Tenda FH451 firmware via stack-based buffer overflow in the WAN configuration endpoint allows unauthenticated attackers to achieve full system compromise through malicious wanmode or PPPOEPassword parameters. Public exploit code exists for this vulnerability, and no patch is currently available. Stack Overflow products are also reported as affected.

Technical ContextAI

Classified as CWE-119 (Buffer Overflow). Affects Fh451 Firmware. A vulnerability was determined in Tenda FH451 1.0.0.9. Affected is the function sub_3C434 of the file /goform/AdvSetWan. This manipulation of the argument wanmode/PPPOEPassword causes stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been publicly disclosed and may be utilized.

RemediationAI

Monitor vendor advisories for a patch. Enable ASLR, DEP/NX, and stack canaries where possible. Restrict network access to the affected service where possible.