Which versions of Tenda are affected by EUVD-2026-21758?

Tenda F451 router firmware 1.0.0.7_cn_svn7958 contains a stack-based buffer overflow that allows authenticated attackers with network access to achieve complete system compromise, affecting…

How to fix or mitigate EUVD-2026-21758?

Within 24 hours: Identify all Tenda F451 devices running firmware 1.0.0.7_cn_svn7958 in your network and document their locations and access controls. Within 7 days: Restrict network access to router management interfaces using firewall rules, VPN-only administration, and strong authentication mechanisms; check Tenda's advisory for firmware updates beyond 1.0.0.7_cn_svn7958. Within 30 days: Evaluate replacing F451 devices with alternative router models from vendors with active security support, or implement segmented network architecture isolating these devices from critical systems.

Tenda EUVD-2026-21758

Q: What is the CVSS score of EUVD-2026-21758?

EUVD-2026-21758 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-2026-6137 HIGH

Buffer Overflow (CWE-119)

2026-04-13 cna@vuldb.com

GHSA-f23m-grxv-hrqj

Tenda Buffer Overflow

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

Analysis Generated

Apr 13, 2026 - 00:32 vuln.today

EUVD ID Assigned

Apr 13, 2026 - 00:22 euvd

EUVD-2026-21758

Analysis Generated

Apr 13, 2026 - 00:22 vuln.today

CVE Published

Apr 13, 2026 - 00:16 nvd

HIGH 7.4

DescriptionCVE.org

A vulnerability was detected in Tenda F451 1.0.0.7_cn_svn7958. The affected element is the function fromAdvSetWan of the file /goform/AdvSetWan. The manipulation of the argument wanmode/PPPOEPassword results in stack-based buffer overflow. It is possible to launch the attack remotely. The exploit is now public and may be used.

AnalysisAI

Stack-based buffer overflow in Tenda F451 router firmware 1.0.0.7_cn_svn7958 allows authenticated remote attackers to achieve complete system compromise (confidentiality, integrity, availability breach) via malformed ADSL/WAN configuration parameters. The vulnerability resides in the fromAdvSetWan function handling wanmode and PPPOEPassword arguments. Publicly available exploit code exists, significantly lowering the barrier to exploitation. CVSS 7.4 (High) with low attack complexity and network-reachable attack vector indicates substantial risk for exposed management interfaces.

Technical ContextAI

This vulnerability affects the web administration interface of Tenda F451 wireless routers, specifically the Advanced WAN Settings endpoint at /goform/AdvSetWan. The fromAdvSetWan function performs inadequate bounds checking when processing user-supplied input for WAN connection mode (wanmode) and PPPoE password (PPPOEPassword) parameters. CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) indicates classic memory corruption due to unsafe string handling in embedded C code. Stack-based buffer overflows occur when data exceeding allocated stack buffer size overwrites adjacent memory, including function return addresses and saved registers. In embedded router firmware with minimal memory protections (no ASLR, DEP, or stack canaries typical in SOHO devices), this class of vulnerability reliably enables arbitrary code execution at the privilege level of the web server process, typically root on embedded Linux systems.

RemediationAI

No vendor-released patch identified at time of analysis. Users should immediately check the Tenda support portal at https://www.tenda.com.cn/ for firmware updates addressing this vulnerability, specifically seeking versions newer than 1.0.0.7_cn_svn7958. As interim risk mitigation: disable remote administration access to prevent Internet-based exploitation, restrict management interface access to trusted internal networks only via firewall rules or router access control lists, change default administrative credentials to strong unique passwords (minimum 16 characters), implement network segmentation isolating the router management plane from untrusted networks, and monitor for unauthorized configuration changes in WAN settings. Organizations should consider replacing affected devices if vendor support is discontinued or patches are not released within acceptable risk windows. Technical details and proof-of-concept code are documented at https://github.com/Jimi-Lab/cve/issues/22 and https://vuldb.com/vuln/357001 for security teams requiring deeper analysis.