What is the CVSS score of CVE-2026-2872?

CVE-2026-2872 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of A21 Firmware are affected by CVE-2026-2872?

Tenda A21 wireless devices are vulnerable to unauthorized MAC filtering configuration changes, potentially allowing attackers to bypass network access controls and gain unauthorized network entry.

Is there a public PoC exploit available for CVE-2026-2872?

Yes, a public proof-of-concept exploit is available for CVE-2026-2872. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-2872?

Within 24 hours: Inventory all Tenda A21 1.0.0.0 devices and assess internet exposure; isolate or restrict access to the /goform/setBlackRule endpoint. Within 7 days: Implement network segmentation to limit device management access to trusted administrative networks only; document all affected devices. Within 30 days: Contact Tenda for patch availability; evaluate replacement with vendor devices offering verified security updates; monitor for exploit activity.

A21 Firmware CVE-2026-2872

HIGH

Buffer Overflow (CWE-119)

2026-02-21 cna@vuldb.com

Buffer Overflow Stack Overflow A21 Firmware

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:04 vuln.today

PoC Detected

Feb 23, 2026 - 20:57 vuln.today

Public exploit code

CVE Published

Feb 21, 2026 - 16:16 nvd

HIGH 8.8

DescriptionCVE.org

A security vulnerability has been detected in Tenda A21 1.0.0.0. This vulnerability affects the function set_device_name of the file /goform/setBlackRule of the component MAC Filtering Configuration Endpoint. Such manipulation of the argument devName/mac leads to stack-based buffer overflow. The attack may be performed from remote. The exploit has been disclosed publicly and may be used.

AnalysisAI

Stack-based buffer overflow in Tenda A21 1.0.0.0 MAC filtering configuration allows remote authenticated attackers to achieve full system compromise through malicious devName/mac parameters. Public exploit code exists for this vulnerability, which remains unpatched. The flaw affects the set_device_name function in the /goform/setBlackRule endpoint with high exploitability due to network accessibility and low attack complexity.

Technical ContextAI

Classified as CWE-119 (Buffer Overflow). Affects A21 Firmware. A security vulnerability has been detected in Tenda A21 1.0.0.0. This vulnerability affects the function set_device_name of the file /goform/setBlackRule of the component MAC Filtering Configuration Endpoint. Such manipulation of the argument devName/mac leads to stack-based buffer overflow. The attack may be performed from remote. The exploit has been disclosed publicly and may be used.

RemediationAI

Monitor vendor advisories for a patch. Enable ASLR, DEP/NX, and stack canaries where possible. Restrict network access to the affected service where possible.