Vulnerability · Published Feb 21, 2026 · Assigned by VulDB

CVE-2026-2872Tenda A21 MAC Filtering Configuration Endpoint setBlackRule set_device_name stack-based overflow

High 8.8

In plain English

A high-severity stack buffer overflow in A21 from Tenda. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.6%top 48.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
Tenda	A21	1.0.0.0

Weakness: CWE-121, CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R

References

VDB-347109 | Tenda A21 MAC Filtering Configuration Endpoint setBlackRule set_device_name stack-based overflow vdb-entry, technical-description
VDB-347109 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
Submit #754634 | Tenda A21 V1.0.0.0 Stack-based Buffer Overflow third-party-advisory
https://github.com/QIU-DIE/cve-nneeww/issues/3 exploit, issue-tracking
https://www.tenda.com.cn/ product