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PatchSiren cyber security CVE debrief

CVE-2026-6239 TP-Link Systems Inc. CVE debrief

A stack-based buffer overflow vulnerability exists in Tapo C520WS v2 in the ONVIF CreateUsers service. The device fails to properly validate the number of XML user nodes during request processing. An authenticated attacker can send a specially crafted ONVIF request containing an excessive number of user entries to trigger memory corruption. Successful exploitation may cause the ONVIF management service to terminate unexpectedly, resulting in a denial-of-service (DoS) condition that disrupts device configuration and management functions.

Vendor
TP-Link Systems Inc.
Product
Tapo C520WS v2
CVSS
MEDIUM 6.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-06
Original CVE updated
2026-07-23
Advisory published
2026-06-06
Advisory updated
2026-07-23

Who should care

Users of Tapo C520WS v2 should apply patches or mitigations to prevent exploitation.

Technical summary

The vulnerability has a CVSS score of 6.8 and is classified as MEDIUM severity. It can be exploited by an authenticated attacker sending a crafted ONVIF request.

Defensive priority

MEDIUM

Recommended defensive actions

  • Apply patches or updates provided by the vendor to fix the vulnerability.
  • Restrict access to the ONVIF CreateUsers service to only trusted users.
  • Monitor device logs for suspicious activity.

Evidence notes

The CVE record and NVD detail pages provide additional information about the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-6239 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-6239

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-6239 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-6239

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://www.tp-link.com/en/support/download/tapo-c520ws/

    f23511db-6c3e-4e32-a477-6aa17d310630

  • Source reference

    Unverified legacy reference

    URL: https://www.tp-link.com/us/support/download/tapo-c520ws/

    f23511db-6c3e-4e32-a477-6aa17d310630

  • Source reference

    Unverified legacy reference

    URL: https://www.tp-link.com/us/support/faq/5120/

    f23511db-6c3e-4e32-a477-6aa17d310630

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.