Whitelist Validation Bypass in TP-Link Tapo C520WS
Key facts
- Attack vector
- Adjacent network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · Low · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-287.
Summary
On Tapo C520WS v2, restricted accounts (for example, hub users) are intended to execute only a limited set of low‑sensitivity operations. Due to a logic flaw in the device’s API authorization mechanism, an attacker can craft requests that leverage legitimate “method mapping” behavior to bypass whitelist restrictions, allowing restricted operations to be masked as permitted requests and executed. Successful exploitation may allow an attacker (with access to a restricted account) to execute unauthorized sensitive operations. Depending on the operation invoked, impact could include device resets, unintended configuration changes, or disruption of normal operation, leading to loss of availability and integrity of the device.
Why it matters now
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
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-2026-05476 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
- TI-2026-05474 Authenticated Stack-based Buffer Overflow in ONVIF DeleteUsers Service on TP-Link Tapo C520WSPriority LOW 29
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34123
- 2026-10-03 Alias added: GHSA-x7cf-gm5r-xq89
References
More TP-Link vulnerabilities
- 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
Sources
- CVE-2026-34123 · CVE Program
- CVE-2026-34123 · NVD
- FIRST EPSS
- GHSA-x7cf-gm5r-xq89 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences