CVE-2026-85109Public exploitNetwork attack vector

Unauthenticated denial of service via unchecked Username copy

Published Sep 3, 2026 · Updated Sep 3, 2026

Buffer overflow in Tenda HG10 300001138 allows remote attackers to leave the device unresponsive through an overlong login Username value. The Boa formLogin handler obtains username with boaGetVar and passes it to strcpy for a fixed-size global buffer without checking its capacity. An unauthenticated POST to /boaform/formLogin is sufficient; published verification left the router unresponsive, while code execution remains unproven.

CVSS severityUnavailable
Unscored
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Buffer overflow in Tenda HG10 300001138 allows remote attackers to leave the device unresponsive through an overlong login Username value. The Boa formLogin handler obtains username with boaGetVar and passes it to strcpy for a fixed-size global buffer without checking its capacity. An unauthenticated POST to /boaform/formLogin is sufficient; published verification left the router unresponsive, while code execution remains unproven.

The record

CVE
CVE-2026-85109
Published
Sep 3, 2026
Updated
Sep 3, 2026
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
HG10
Classifications
CWE-119, CWE-120, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 3, 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=300001138

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · HG10version=300001138

Published CVSS scores

10.0VulDB CNAAV:N/AC:L/Au:N/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
9.8VulDB CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
9.8VulDB CNACVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
9.3VulDB CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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