What is the CVSS score of CVE-2026-2874?

CVE-2026-2874 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-2026-2874?

A high-severity vulnerability (CVE-2026-2874, CVSS 8.8) affects Tenda A21 wireless routers with active public exploits available.

Is there a public PoC exploit available for CVE-2026-2874?

Yes, a public proof-of-concept exploit is available for CVE-2026-2874. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-2874?

Within 24 hours: Inventory all Tenda A21 1.0.0.0 devices in production and isolate affected units from critical networks if possible. Within 7 days: Implement network segmentation to restrict administrative access to affected devices and enable enhanced monitoring for suspicious activity. Within 30 days: Replace vulnerable Tenda A21 devices with patched firmware versions once available, or procure alternative router solutions from vendors with active security support.

A21 Firmware CVE-2026-2874

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 - 20:09 vuln.today

Public exploit code

CVE Published

Feb 21, 2026 - 18:15 nvd

HIGH 8.8

DescriptionCVE.org

A flaw has been found in Tenda A21 1.0.0.0. Impacted is the function form_fast_setting_wifi_set of the file /goform/fast_setting_wifi_set. Executing a manipulation of the argument ssid can lead to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been published and may be used.

AnalysisAI

Remote code execution in Tenda A21 1.0.0.0 firmware via stack-based buffer overflow in the WiFi settings endpoint allows authenticated attackers to execute arbitrary code with full system privileges. The vulnerability exists in the fast_setting_wifi_set function where unsanitized SSID parameter input can overflow the stack, and public exploit code is currently available. No patch has been released for this high-severity vulnerability affecting both the A21 firmware and Stack Overflow products.

Technical ContextAI

Classified as CWE-119 (Buffer Overflow). Affects A21 Firmware. A flaw has been found in Tenda A21 1.0.0.0. Impacted is the function form_fast_setting_wifi_set of the file /goform/fast_setting_wifi_set. Executing a manipulation of the argument ssid can lead to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been published 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.