How severe is CVE-2026-1638?

CVE-2026-1638 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-1638 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-1638?

CVE-2026-1638 affects Tenda Ac21 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-1638?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-1638 have an EU (EUVD) identifier?

Yes. CVE-2026-1638 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5015.

When was CVE-2026-1638 published?

CVE-2026-1638 was published on 2026-01-30 and last updated on 2026-06-17.

CVE-2026-1638

CVE-2026-1638 is a medium-severity vulnerability in Tenda Ac21 Firmware with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-77.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 6.5
CVSS v4: 2.1
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-5015
Weakness: CWE-77
Affected product: Tenda Ac21 Firmware
Published: 2026-01-30
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-1638?: 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.
How severe is CVE-2026-1638?: CVE-2026-1638 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-1638 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-1638?: CVE-2026-1638 affects Tenda Ac21 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-1638?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-1638 have an EU (EUVD) identifier?: Yes. CVE-2026-1638 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5015.
When was CVE-2026-1638 published?: CVE-2026-1638 was published on 2026-01-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:tenda:ac21_firmware:16.03.08.16:*:*:*:*:*:*:*

More vulnerabilities in Tenda Ac21 Firmware

CVE-2025-9605 — Critical (CVSS 9.8): A security vulnerability has been detected in Tenda AC21 and AC23 16.03.08.16. Affected is the function…
CVE-2026-4565 — High (CVSS 8.8): A vulnerability was detected in Tenda AC21 16.03.08.16. Impacted is the function formSetQosBand of the file…
CVE-2026-1637 — High (CVSS 8.8): A vulnerability was identified in Tenda AC21 16.03.08.16. The affected element is the function fromAdvSetMacMtuWan of…
CVE-2025-13446 — High (CVSS 8.8): A vulnerability has been found in Tenda AC21 16.03.08.16. This vulnerability affects unknown code of the file…
CVE-2025-13445 — High (CVSS 8.8): A flaw has been found in Tenda AC21 16.03.08.16. This affects an unknown part of the file /goform/SetIpMacBind.…
CVE-2025-12611 — High (CVSS 8.8): A vulnerability was identified in Tenda AC21 16.03.08.16. This vulnerability affects the function formSetPPTPServer of…

All CVEs affecting Tenda Ac21 Firmware →

Other CWE-77 (Command Injection) vulnerabilities

CVE-2026-23652 — Critical (CVSS 10.0): Improper neutralization of special elements used in a command ('command injection') in Microsoft Power Pages allows an…
CVE-2025-59818 — Critical (CVSS 10.0): This vulnerability allows authenticated attackers to execute arbitrary commands on the underlying system using the file…
CVE-2025-64093 — Critical (CVSS 10.0): Remote Code Execution vulnerability that allows unauthenticated attackers to inject arbitrary commands into the…
CVE-2025-64090 — Critical (CVSS 10.0): This vulnerability allows authenticated attackers to execute commands via the hostname of the device.
CVE-2025-61492 — Critical (CVSS 10.0): A command injection vulnerability in the execute_command function of terminal-controller-mcp 0.1.7 allows attackers to…
CVE-2025-10035 — Critical (CVSS 10.0): A deserialization vulnerability in the License Servlet of Fortra's GoAnywhere MFT allows an actor with a validly forged…

Browse all CWE-77 (Command Injection) vulnerabilities →