Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Attack requirements (AT:N) | No attack requirements |
| Privileges required (PR:H) | High privileges required |
| User interaction (UI:N) | No user interaction |
| Confidentiality (VC:H) | High confidentiality impact |
| Integrity (VI:H) | High integrity impact |
| Availability (VA:H) | High availability impact |
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/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
About Tenda G300-F Firmware
CVE-2026-25857 affects Tenda G300-F Firmware, a product from Tenda. Before acting, confirm where Tenda G300-F Firmware runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: Tenda G300-F router firmware version 16.01.14.2 and prior contain an OS command injection vulnerability in the WAN diagnostic functionality (formSetWanDiag). The implementation constructs a shell command that invokes curl and incorporates attacker-controlled input into the command line without adequate neutralization. As a result, a remote attacker with access to the affected management interface can inject additional shell syntax and execute arbitrary commands on the device with the privileges of the management process.
The weakness class is OS Command Injection. Untrusted input is passed to the operating system shell, letting an attacker run commands.
Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Tenda G300-F Firmware |
| Affected versions | G300-F Firmware up to and including 16.01.14.2 |
| Published | Feb 7, 2026 |
| Last modified | Jun 17, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | disclosure@vulncheck.com |
How to detect it
- Inventory every instance of Tenda G300-F Firmware and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Tenda G300-F Firmware named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Tenda G300-F Firmware to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-78: OS Command Injection More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
In Tenda AC7 v15.03.06.44, the wanSpeed parameter of the route /goform/AdvSetMacMtuWan has a stack buffer overflow vulnerability that can lead to remote arbitrary code execution.
Tenda AC7 v15.03.06.44 contains a stack buffer overflow vulnerability in the /goform/AdvSetMacMtuWan interface via the mac parameter.
Tenda AC7 v15.03.06.44 contains a stack buffer overflow vulnerability in the /goform/AdvSetMacMtuWan interface via the cloneType parameter.
Tenda AC7 v15.03.06.44 contains a stack buffer overflow vulnerability in the /goform/AdvSetMacMtuWan interface via the wanMTU parameter.
A command injection vulnerability exists in Tenda AC18 V15.03.05.05_multi. The vulnerability is located in the /goform/SetSambaCfg interface, where improper handling of the guestuser parameter allows attackers to execute arbitrary system commands.
Tenda AC6 15.03.05.16_multi is vulnerable to Buffer Overflow in the formSetCfm function via the funcname, funcpara1, and funcpara2 parameters.
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