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CVE-2026-6240: CWE-121 Stack-based buffer overflow in TP-Link Systems Inc. Tapo C520WS v2

0
Medium
VulnerabilityCVE-2026-6240cvecve-2026-6240cwe-121
Published: Fri Jun 05 2026 (06/05/2026, 23:51:39 UTC)
Source: CVE Database V5
Vendor/Project: TP-Link Systems Inc.
Product: Tapo C520WS v2

Description

CVE-2026-6240 is a stack-based buffer overflow vulnerability in the TP-Link Tapo C520WS v2 camera's ONVIF DeleteUsers service. It arises from insufficient boundary checks when processing multiple user deletion parameters. An authenticated attacker can exploit this by sending a crafted request with an excessive number of identifiers, causing a stack overflow. Successful exploitation may lead to a service crash or deadlock, resulting in denial of service that disrupts device management and monitoring. The vulnerability has a CVSS 4. 0 base score of 6. 8, indicating medium severity. There is no confirmed patch or official remediation available at this time. No known exploits in the wild have been reported.

CVSS v4.0

Score 6.8medium

Attack Vector
Adjacent Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
High
User Interaction
None
Vuln. Confidentiality
None
Vuln. Integrity
None
Vuln. Availability
High
Subsq. Confidentiality
None
Subsq. Integrity
None
Subsq. Availability
None
CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 06/06/2026, 00:33:45 UTC

Technical Analysis

This vulnerability (CVE-2026-6240) affects the TP-Link Tapo C520WS v2 device in its ONVIF DeleteUsers service. It is a stack-based buffer overflow (CWE-121) caused by inadequate boundary validation when handling multiple user deletion parameters. An attacker with authentication privileges can send a malicious request containing an excessive number of user identifiers, overflowing the stack memory. This can cause the service to crash or deadlock, resulting in denial of service that impacts device management and monitoring functions. The CVSS 4.0 vector indicates the attack requires adjacent network access, low attack complexity, no user interaction, and high privileges. No patch or vendor advisory detailing remediation is currently available.

Potential Impact

Exploitation of this vulnerability can cause a denial of service by crashing or deadlocking the affected service on the device. This disrupts device management and monitoring capabilities, potentially impacting operational availability. There is no indication of code execution or data disclosure from the provided information.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the ONVIF DeleteUsers service to trusted and authenticated users only. Monitor for unusual activity related to user deletion requests. Avoid exposing the device management interface to untrusted networks.

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Technical Details

Data Version
5.2
Assigner Short Name
TPLink
Date Reserved
2026-04-13T17:10:23.938Z
Cvss Version
4.0
State
PUBLISHED
Remediation Level
null

Threat ID: 6a23675be29bf47b50dbe8d8

Added to database: 6/6/2026, 12:18:35 AM

Last enriched: 6/6/2026, 12:33:45 AM

Last updated: 6/6/2026, 1:38:31 AM

Views: 4

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