CVE-2026-9389Public exploitNetwork attack vector

Authenticated code execution via unchecked sprintf copy

Published May 24, 2026 · Updated May 24, 2026

Stack-based buffer overflow in Tenda F456 Firmware 1.0.0.5 allows remote authenticated users to execute code or crash the router. The frmL7ImForm handler for /goform/L7Im passes the user-controlled page value through sprintf without a length check into stack buffer s. Low-privileged network access to the management interface is required; successful exploitation can interrupt routing or execute code in the httpd process.

CVSS severity8.8
High
EPSS probability0.44%
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 F456 Firmware 1.0.0.5 allows remote authenticated users to execute code or crash the router. The frmL7ImForm handler for /goform/L7Im passes the user-controlled page value through sprintf without a length check into stack buffer s. Low-privileged network access to the management interface is required; successful exploitation can interrupt routing or execute code in the httpd process.

The record

CVE
CVE-2026-9389
Published
May 24, 2026
Updated
May 24, 2026
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
F456 Firmware
Classifications
CWE-120, CWE-119, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 24, 2026CVE publishedPublication date reported by the CVE source.
  2. May 24, 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=1.0.0.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · F456 Firmwareversion=1.0.0.5

Published CVSS scores

9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C
7.4INCIBE-CERTCVSS: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
8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1210Exploitation of Remote Services

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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