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Ac15 CVE-2026-5830

| EUVDEUVD-2026-20828 HIGH
Stack-based Buffer Overflow (CWE-121)
2026-04-09 VulDB
7.4
CVSS 4.0 · Vendor: VulDB
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Attack ChainAIDerived

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

  1. Access
    Authenticate to Tenda AC15 web interface
  2. Delivery
    Send crafted POST to /goform/SysToolChangePwd
  3. Exploit
    Overflow oldPwd/newPwd parameter in websGetVar
  4. Execution
    Corrupt stack and overwrite return address
  5. Impact
    Execute arbitrary code on device

Vulnerability Assessment

Weakness
CWE
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.

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

2
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
1
Sightings
Data Quality
6 sources
Confidence: High

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
No
Human Impact
High
Technical Impact
Total

Priority Score

57
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +37
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

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.

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.

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