CVE-2026-6240
Authenticated Stack-based Buffer Overflow in ONVIF DeleteUsers Service on TP-Link Tapo C520WS
Description
A stack-based buffer overflow vulnerability exists in Tapo C520WS v2 in the ONVIF DeleteUsers service, due to insufficient boundary checks when handling multiple user deletion parameters. An authenticated attacker can send a crafted malicious request containing an excessive number of identifiers to overflow stack memory. Successful exploitation may result in a service crash or deadlock, leading to DoS affecting device management and monitoring functionality.
INFO
Published Date :
June 6, 2026, 12:16 a.m.
Last Modified :
June 6, 2026, 12:16 a.m.
Remotely Exploit :
No
Source :
f23511db-6c3e-4e32-a477-6aa17d310630
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | f23511db-6c3e-4e32-a477-6aa17d310630 | ||||
| CVSS 4.0 | MEDIUM | f23511db-6c3e-4e32-a477-6aa17d310630 |
Solution
- Update the Tapo C520WS firmware to the latest version.
- Apply vendor patches for ONVIF service vulnerabilities.
- Avoid excessive user deletion requests.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-6240.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-6240 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-6240
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-6240 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-6240 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by f23511db-6c3e-4e32-a477-6aa17d310630
Jun. 06, 2026
Action Type Old Value New Value Added Description A stack-based buffer overflow vulnerability exists in Tapo C520WS v2 in the ONVIF DeleteUsers service, due to insufficient boundary checks when handling multiple user deletion parameters. An authenticated attacker can send a crafted malicious request containing an excessive number of identifiers to overflow stack memory. Successful exploitation may result in a service crash or deadlock, leading to DoS affecting device management and monitoring functionality. Added CVSS V4.0 AV:A/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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 Added CWE CWE-121 Added Reference https://www.tp-link.com/en/support/download/tapo-c520ws/#Firmware-Release-Notes Added Reference https://www.tp-link.com/us/support/download/tapo-c520ws/#Firmware-Release-Notes Added Reference https://www.tp-link.com/us/support/faq/5120/