CVE-2026-2886Public exploitNetwork attack vector

Authenticated code execution via unchecked sprintf

Published Feb 21, 2026 · Updated Feb 21, 2026

Stack-based buffer overflow in Tenda A21 1.0.0.0 allows remote authenticated users to execute code via a crafted devName value. The set_device_name function passes devName to sprintf without a length check, writing it with a suffix into a fixed 256-byte stack buffer. Low-privileged access to the management endpoint is required; exploitation can overwrite the return address to run code as root or crash the web interface.

CVSS severity8.8
High
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Tenda A21 1.0.0.0 allows remote authenticated users to execute code via a crafted devName value. The set_device_name function passes devName to sprintf without a length check, writing it with a suffix into a fixed 256-byte stack buffer. Low-privileged access to the management endpoint is required; exploitation can overwrite the return address to run code as root or crash the web interface.

The record

CVE
CVE-2026-2886
Published
Feb 21, 2026
Updated
Feb 21, 2026
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
A21
Classifications
CWE-121, CWE-119, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · A21version=1.0.0.0

Published CVSS scores

9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.4VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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