AC18: Insufficient Verification of Data Authenticity
CVE-2026-129258 is a critical-severity insufficient verification of data authenticity vulnerability in AC18 from Tenda, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected AC18 versions: 15.03.05.05_multi; 15.03.05.19 Build 6318. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far, and no EPSS exploitation forecast has been published yet.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of AC18 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
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
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- 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:H/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (vuldb.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.5 | High | CNA (vuldb.com) |
| CVSS 3.1 | 9.1 | Critical | CNA (vuldb.com) |
| CVSS 2.0 | 8.3 | High | CNA (vuldb.com) |
Official description
A vulnerability was identified in Tenda AC18 15.03.05.05_multi/15.03.05.19 Build 6318. Affected by this vulnerability is an unknown functionality of the file /cgi-bin/upgrade of the component Firmware Upgrade Handler. Such manipulation of the argument upgradeFile leads to insufficient verification of data authenticity. The attack may be launched remotely. The exploit is publicly available and might be used.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Insufficient Verification of Data Authenticity
The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
More Insufficient Verification of Data Authenticity vulnerabilities (CWE-345)
Timeline
- CVE record published.
References
Other references
Other vulnerabilities in AC18
- 10.0 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
Recent Insufficient Verification of Data Authenticity vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
- 9.6 Critical severity
- 8.9 High severity
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