What is the CVSS score of EUVD-2026-20828?

EUVD-2026-20828 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. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for EUVD-2026-20828?

Yes, a public proof-of-concept exploit is available for EUVD-2026-20828. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate EUVD-2026-20828?

Within 24 hours: Inventory all Tenda AC15 routers in production and identify firmware versions via administrative interface. Within 7 days: Restrict administrative access to AC15 routers to a limited security team; disable remote management if not operationally required; rotate all router credentials and enforce strong passwords. Within 30 days: Contact Tenda for patch availability timeline; evaluate replacement with patched alternative or vendor models with confirmed security updates; implement network segmentation to limit blast radius if compromise occurs.

Ac15 EUVD-2026-20828

| CVE-2026-5830 HIGH

Stack-based Buffer Overflow (CWE-121)

2026-04-09 VulDB

Buffer Overflow Stack Overflow Tenda Ac15

7.4

CVSS 4.0 · Vendor: VulDB

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Authenticate to Tenda AC15 web interface
Delivery

Send crafted POST to /goform/SysToolChangePwd
Exploit

Overflow oldPwd/newPwd parameter in websGetVar
Execution

Corrupt stack and overwrite return address
Impact

Execute arbitrary code on device

Vulnerability Assessment

Weakness	CWE CWE-121 ASVS 5.0 V15 - Secure Coding and Architecture Stack buffer bounds checking MITRE ATT&CK 1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	Requires authenticated access to Tenda AC15 router running firmware 15.03.05.18. Attacker must be logged into the web interface to access /goform/SysToolChangePwd and send crafted oldPwd/newPwd/cfmPwd parameters triggering stack buffer overflow.
Impact	High-severity stack overflow in authenticated password change function. CVSS 8.8 reflects confidentiality, integrity, and availability impact. Moderate observed exploitation activity. Public exploit availability and authentication requirement (PR:L) reduce blast radius compared to unauthenticated flaws, but compromised accounts or default credentials enable full system compromise on vulnerable Tenda AC15 devices.
Exploit ScenarioDerived	Attacker with valid credentials accesses /goform/SysToolChangePwd endpoint and sends oversized oldPwd/newPwd/cfmPwd parameters to websGetVar function, triggering stack buffer overflow. Publicly available exploit code enables remote code execution with device privileges.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Apr 09, 2026

Stack-based buffer overflow in Tenda AC15 router firmware 15.03.05.18 websGetVar function allows authenticated remote attackers to execute arbitrary code with high impact to confidentiality, integrity, and availability. The vulnerability resides in /goform/SysToolChangePwd endpoint where manipulation of oldPwd, newPwd, or cfmPwd parameters triggers memory corruption. Publicly available exploit code exists. Exploitation requires low-privilege authenticated access but no user interaction, making it readily exploitable once credentials are obtained.

RemediationAI

No vendor-released patch identified at time of analysis. Tenda has not published security advisories addressing CVE-2026-5830 per https://www.tenda.com.cn/. Recommended immediate actions: restrict administrative interface access to trusted management networks only via firewall rules, disable remote administration features, implement strong unique credentials, monitor for unauthorized password change attempts in device logs. Consider replacement with actively maintained router firmware if vendor does not issue timely patch. Consult VulDB advisory https://vuldb.com/vuln/356277 and threat intelligence https://vuldb.com/vuln/356277/cti for updates. Organizations should evaluate device retirement if patch unavailable within acceptable risk timeframe given confirmed exploit availability.

Affected VersionsENISA

AC15 15.03.05.18

Affected Packages

euvd ac15 no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Stack buffer overflow (CWE-121) in websGetVar function processing password change parameters. Insufficient input validation on oldPwd/newPwd/cfmPwd arguments permits oversized data to corrupt stack memory. Attack vector is network-accessible (AV:N) with low complexity (AC:L), requiring only authenticated low-privilege access (PR:L). Root cause is unbounded string copy operation in embedded web server password management routine.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (VulDB) 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

Primary rating from Vendor (VulDB) · only source for this CVE.

CVSS VectorVendor: VulDB

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

Low

User Interaction

None

Vulnerable system: Confidentiality

High

Vulnerable system: Integrity

High

Vulnerable system: Availability

High

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

Lifecycle Timeline

PoC Detected

Apr 09, 2026 - 02:16 vuln.today

Public exploit code

CVE Published

Apr 09, 2026 - 01:30 nvd

HIGH 7.4

DescriptionCVE.org

A vulnerability was identified in Tenda AC15 15.03.05.18. This affects the function websGetVar of the file /goform/SysToolChangePwd. Such manipulation of the argument oldPwd/newPwd/cfmPwd leads to stack-based buffer overflow. The attack can be executed remotely. The exploit is publicly available and might be used.

Executive ViewAI

Why It Matters

Tenda AC15 routers running firmware 15.03.05.18 contain a stack buffer overflow in the password change function that allows authenticated users to execute arbitrary code with full system compromise. This affects organizations relying on Tenda AC15 devices for network access, as any employee or contractor with router credentials can escalate to complete device control without additional user interaction.

Business Impact: High

Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: (1) Disable WAN-accessible administration interfaces and restrict management access to trusted internal networks only; (2) Implement network-level access controls limiting who can reach router management ports; (3) Change all default/shared administrative credentials to unique, complex passwords; (4) Monitor router logs for suspicious /goform/SysToolChangePwd requests; (5) Isolate affected routers from critical infrastructure; (6) Evaluate vendor communication for patch release timeline and prepare contingency replacement devices.

Threat Intelligence Overview

EPSS Score

0.0%

Top 86% exploitable

Exploit

POC

Public exploit code exists

Social Media

Sightings

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

Vulnrichment CIRCL

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision

Scheduled

Exploitation

Poc

System Exposure· derived

Open

Automatable

Human Impact

High

Technical Impact

Total

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +37

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Stack-based Buffer Overflow HIGH

A stack-based buffer overflow occurs when a program writes more data to a buffer located on the stack than it was allocated to hold.