Tapo C520WS v2: Improper Authentication
CVE-2026-34123 is a high-severity improper authentication vulnerability in Tapo C520WS v2 from TP-Link, with a CVSS 4.0 base score of 7.0 out of 10. It can be exploited from the same local network by an attacker with a low-privileged account, without any action from a user. The record lists version 1.2.6 Build 260528 as the first without the flaw, so updating Tapo C520WS v2 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.15% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Tapo C520WS v2 to 1.2.6 Build 260528 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| TP-Link | Tapo C520WS v2 | before 1.2.6 Build 260528 | 1.2.6 Build 260528 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- NoneNo loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- LowLimited loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/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. Scored by CNA.
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Other vulnerabilities in Tapo C520WS v2
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Improper Authentication vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 8.3 High severity
- 8.6 High severity
- 8.8 High severity
- 9.8 Critical severity
Spotted an error? Tell us.