Tapo C110 v2: Use of Externally-Controlled Format String
CVE-2026-6250 is a high-severity use of externally-controlled format string vulnerability in Tapo C110 v2 from TP-Link, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 1.5.4 Build 260428 as the first without the flaw, so updating Tapo C110 v2 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.46% 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 C110 v2 to 1.5.4 Build 260428 or a later version.
- Update Tapo C110 Firmware to 1.5.4 or a later version.
- Read the advisory on tp-link.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| TP-Link | Tapo C110 v2 | before 1.5.4 Build 260428 | 1.5.4 Build 260428 |
| TP-Link | Tapo C110 Firmware | before 1.5.4 | 1.5.4 |
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.0 | High | CNA |
| CVSS 3.1 | 8.1 | High | NVD |
Official description
An authenticated format string vulnerability exists in the ONVIF service of Tapo C110 v2 due to improper handling of user-controlled input. Externally controlled data is interpreted as a format string, which can be used to manipulate stack memory, including control flow data such as return addresses. A remote authenticated attacker may redirect execution flow to existing internal functions, triggering an unauthorized factory reset, leading to loss of configuration, deletion of stored credentials and service disruption.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Externally-Controlled Format String
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
How developers prevent this class of flaw
- Choose a language that is not subject to this flaw.
- Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
- Run compilers and linkers with high warning levels, since they may detect incorrect usage.
More Use of Externally-Controlled Format String vulnerabilities (CWE-134)
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
Advisories
Patches and release notes
Recent Use of Externally-Controlled Format String vulnerabilities
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
- 7.2 High severity
- 8.1 High severity
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