Which versions of Tenda F456 are affected by EUVD-2026-25800?

Tenda F456 routers running firmware 1.0.0.5 are vulnerable to remote code execution through a buffer overflow in the HTTP management interface, exploitable by authenticated attackers using publicly…

How to fix or mitigate EUVD-2026-25800?

Within 24 hours: Identify all Tenda F456 devices in production and document firmware versions via device management systems or network scans. Within 7 days: disable remote management access to affected routers (disable WAN-side HTTP/HTTPS administration), enforce strong unique credentials on all remaining local access paths, and segment router management to restricted administrative networks. Within 30 days: contact Tenda support for firmware updates; monitor for vendor patch release at Tenda security advisories; plan replacement with routers from vendors with active security support if patch timeline exceeds 60 days.

Tenda F456 EUVD-2026-25800

Q: What is the CVSS score of EUVD-2026-25800?

EUVD-2026-25800 has a CVSS 4.0 base score of 7.4 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

| CVE-2026-7100 HIGH

Buffer Overflow (CWE-119)

2026-04-27 cna@vuldb.com

Buffer Overflow Tenda

7.4

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

7.4 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Re-analysis Queued

Apr 27, 2026 - 19:07 vuln.today

cvss_changed

Analysis Generated

Apr 27, 2026 - 09:31 vuln.today

EUVD ID Assigned

Apr 27, 2026 - 09:22 euvd

EUVD-2026-25800

Analysis Generated

Apr 27, 2026 - 09:22 vuln.today

CVE Published

Apr 27, 2026 - 09:16 nvd

HIGH 7.4

DescriptionCVE.org

A flaw has been found in Tenda F456 1.0.0.5. The impacted element is the function fromNatlimitof of the file /goform/Natlimit of the component httpd. Executing a manipulation can lead to buffer overflow. The attack may be launched remotely. The exploit has been published and may be used.

AnalysisAI

Buffer overflow in Tenda F456 router firmware 1.0.0.5 allows authenticated remote attackers to execute arbitrary code or crash the device via crafted HTTP requests to the /goform/Natlimit endpoint. Public exploit code exists on GitHub (Litengzheng/vuldb_new), demonstrating practical exploitability. EPSS data unavailable, but with POC published and AV:N/AC:L indicating straightforward network exploitation, this poses significant risk to internet-exposed router management interfaces with weak or default credentials.

Technical ContextAI

The vulnerability resides in the httpd component of Tenda F456 router firmware, specifically within the fromNatlimit function that handles requests to the /goform/Natlimit endpoint. This is classified as CWE-119 (Improper Restriction on Operations within Bounds of Memory Buffer), indicating insufficient input validation before copying user-controlled data into fixed-size buffers. Embedded web servers in SOHO routers frequently suffer from such issues due to limited memory protection mechanisms and lack of modern compiler mitigations like stack canaries or ASLR. The /goform/ path pattern is characteristic of Tenda's router management interface, where form handlers directly process CGI-style parameters without adequate boundary checks.

RemediationAI

No vendor-released patch identified at time of analysis - Tenda has not published security advisories or firmware updates addressing CVE-2026-7100 on their official website. Until patched firmware becomes available, implement network-level compensating controls: (1) Disable remote management access to the router's web interface from WAN/internet side, restricting admin access to LAN-only (check router settings under Remote Management or similar). Trade-off: prevents legitimate remote administration. (2) Change default administrator credentials to strong unique passwords (20+ characters, mixed case/numbers/symbols). Trade-off: increases support complexity but essential baseline control. (3) Place router management interface behind VPN access if remote administration is required. Trade-off: adds infrastructure complexity. (4) Monitor for unusual authentication attempts or POST requests to /goform/* endpoints in router logs. Trade-off: limited logging capability on consumer routers. Consider replacing device with actively supported router model from vendors with established security response programs.