Tenda AC21 mDMZSetCfg command injection
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Code execution
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-77.
Summary
A security flaw has been discovered in Tenda AC21 1.1.1.1/1.dmzip/16.03.08.16. The impacted element is the function mDMZSetCfg of the file /goform/mDMZSetCfg. The manipulation of the argument dmzIp results in command injection. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Tenda | AC21 | 1.1.1.1; 1.dmzip; 16.03.08.16 | — | No fix listed | CNA |
- AC21 VendorTenda Affected 1.1.1.1; 1.dmzip; 16.03.08.16 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-1638
- 2026-10-03 Alias added: GHSA-2wx5-jfx2-287m
References
More Tenda Ac21 Firmware vulnerabilities
- TI-2025-08798 Tenda AC21/AC23 GetParentControlInfo stack-based overflow CVSS 4.0CRITICAL 9.3
- TI-2026-01322 Tenda AC21 AdvSetMacMtuWan fromAdvSetMacMtuWan stack-based overflow CVSS 4.0HIGH 8.7
- TI-2025-12293 Tenda AC21 SetSysTimeCfg stack-based overflow CVSS 4.0HIGH 8.7
- TI-2025-12292 Tenda AC21 SetIpMacBind stack-based overflow CVSS 4.0HIGH 8.7
- TI-2025-11565 Tenda AC21 SetPptpServerCfg formSetPPTPServer buffer overflow CVSS 4.0HIGH 8.7
- TI-2025-10159 Tenda AC21 SetStaticRouteCfg sscanf buffer overflow CVSS 4.0HIGH 8.7
Sources
- CVE-2026-1638 · CVE Program
- CVE-2026-1638 · NVD
- FIRST EPSS
- GHSA-2wx5-jfx2-287m · GitHub Advisory Database · CC BY 4.0
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