What is the CVSS score of CVE-2026-2873?

CVE-2026-2873 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-2026-2873?

A critical vulnerability in Tenda A21 wireless routers allows unauthenticated attackers to disable Wi-Fi scheduling functionality and potentially gain unauthorized network access.

Is there a public PoC exploit available for CVE-2026-2873?

Yes, a public proof-of-concept exploit is available for CVE-2026-2873. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-2873?

Within 24 hours: Inventory all Tenda A21 devices in your environment and isolate affected units from production networks if possible. Within 7 days: Implement network segmentation to restrict administrative access to affected devices and disable the vulnerable /goform/openSchedWifi endpoint at the firewall level. Within 30 days: Replace all Tenda A21 devices with alternative solutions from vendors with active security support, or contact Tenda for workaround guidance.

A21 Firmware CVE-2026-2873

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 - 20:56 vuln.today

Public exploit code

CVE Published

Feb 21, 2026 - 17:15 nvd

HIGH 8.8

DescriptionCVE.org

A vulnerability was detected in Tenda A21 1.0.0.0. This issue affects the function setSchedWifi of the file /goform/openSchedWifi. Performing a manipulation of the argument schedStartTime/schedEndTime results in stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit is now public and may be used.

AnalysisAI

Stack-based buffer overflow in Tenda A21 firmware allows remote attackers with valid credentials to achieve complete system compromise through malicious input to the schedStartTime/schedEndTime parameters in the openSchedWifi function. Public exploit code exists for this vulnerability, and no patch is currently available. This affects confidentiality, integrity, and availability with high severity (CVSS 8.8).

Technical ContextAI

Classified as CWE-119 (Buffer Overflow). Affects A21 Firmware. A vulnerability was detected in Tenda A21 1.0.0.0. This issue affects the function setSchedWifi of the file /goform/openSchedWifi. Performing a manipulation of the argument schedStartTime/schedEndTime results in stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit is now public 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.