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TI-2026-05474 Aliases CVE-2026-6240GHSA-qv33-m6vq-mqmr

Authenticated Stack-based Buffer Overflow in ONVIF DeleteUsers Service on TP-Link Tapo C520WS

Priority LOW 29CWE-121Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
High
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0018 7th percentileScored 2026-11-07
Fix Fixed Tapo C520WS v2 (TP-Link Systems Inc.): 1.2.6 Build 260528

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
TP-LinkTapo C520WS v2before 1.2.6 Build 2605281.2.6 Build 260528Patch availableCNA
  • Tapo C520WS v2 VendorTP-Link Affected before 1.2.6 Build 260528 Fixed in 1.2.6 Build 260528 Patch available CNA

Remediation

  • Fix · CNA Tapo C520WS v2 (TP-Link Systems Inc.) Fixed in 1.2.6 Build 260528

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    TP-Link Systems Tapo C520WS v2 — tp-link.com/us/support/faq/5120

    5 records Highest priority Priority LOW 5 LOW

    Other records, highest priority first

    • TI-2026-26445 Whitelist Validation Bypass in TP-Link Tapo C520WSPriority LOW 30
    • TI-2026-05476 Authenticated Format String Vulnerability in ONVIF Subscribe Service on TP-Link Tapo C520WSPriority LOW 29
    • TI-2026-05475 Authenticated Format String Vulnerability in ONVIF AddScopes Method on TP-Link Tapo C520WSPriority LOW 29
    Show all 5 records → Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-6240
  2. 2026-10-03 Alias added: GHSA-qv33-m6vq-mqmr

References

Patch 2

Advisory 1

  • TI-2023-16571 TP-Link TL-WR940N V2/V4, TL-WR841N V8/V10, and TL-WR740N V1/V2 was discovered to contain… KEVCVSS 3.1HIGH 8.8
  • TI-2023-01313 Command injection in TP-Link Archer AX21 KEVCVSS 3.1HIGH 8.8
  • TI-2020-14907 TP-Link TL-WA855RE V5 20200415-rel37464 devices allow an unauthenticated attacker (on the… KEVCVSS 3.1HIGH 8.8
  • TI-2025-08589 Authenticated RCE via Parental Control command injection KEVCVSS 4.0HIGH 8.6
  • TI-2015-02672 Directory traversal vulnerability in TP-LINK Archer C5 (1.2) with firmware before 150317… KEVCVSS 3.1HIGH 7.5
  • TI-2023-27456 Authentication bypass by spoofing in TP-Link TL-WR841N KEVCVSS 3.1MEDIUM 6.5
See all 636 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences