CVE-2026-2908Public exploitNetwork attack vector

Authenticated code execution via unbounded Ethtype formatting

Published Feb 22, 2026 · Updated Feb 22, 2026

Stack-based buffer overflow in Tenda HG9 firmware 300001138 allows remote authenticated users to crash httpd or execute code. The formLoopBack handler prepends 0x to an unbounded Ethtype value with sprintf and writes the result into an eight-byte stack buffer. A low-privilege session and apply=1 reach the path; overwriting the saved return address grants root-level code execution, while shorter corruption crashes httpd.

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 HG9 firmware 300001138 allows remote authenticated users to crash httpd or execute code. The formLoopBack handler prepends 0x to an unbounded Ethtype value with sprintf and writes the result into an eight-byte stack buffer. A low-privilege session and apply=1 reach the path; overwriting the saved return address grants root-level code execution, while shorter corruption crashes httpd.

The record

CVE
CVE-2026-2908
Published
Feb 22, 2026
Updated
Feb 22, 2026
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
HG9
Classifications
CWE-119, CWE-121, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 22, 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 privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · HG9version=300001138

Published CVSS scores

8.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
7.4NVDCVSS: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-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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