CVE-2025-7855Public exploitNetwork attack vector

Authenticated code execution via unbounded sprintf

Published Jul 19, 2025 · Updated Jul 22, 2025

Stack-based buffer overflow in Tenda FH451 1.0.0.9 allows remote authenticated users to execute code via a crafted page parameter. The fromqossetting handler passes the page-derived v8 value to sprintf without a length check, overflowing the stack buffer s. Access to the router's QoS management endpoint is required; exploitation can crash the service or execute code on the device.

CVSS severity8.7
High
EPSS probability1.04%
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 FH451 1.0.0.9 allows remote authenticated users to execute code via a crafted page parameter. The fromqossetting handler passes the page-derived v8 value to sprintf without a length check, overflowing the stack buffer s. Access to the router's QoS management endpoint is required; exploitation can crash the service or execute code on the device.

The record

CVE
CVE-2025-7855
Published
Jul 19, 2025
Updated
Jul 22, 2025
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
FH451
Classifications
CWE-119, CWE-121, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 22, 2025Record 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=1.0.0.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · FH451version=1.0.0.9

Published CVSS scores

8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.7VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8VulDBCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C

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