CVE-2026-9431Public exploitNetwork attack vector

Authenticated code execution via unchecked sprintf

Published May 25, 2026 · Updated May 25, 2026

Stack-based buffer overflow in Tenda F1202 1.2.0.20(408) allows remote authenticated users to execute code via a crafted PPTP request. The fromPptpUserAdd handler passes a user-controlled username to sprintf without a length check when opttype is 1, overflowing stack buffer s__3. Low-privilege access to the network management interface is required; a crafted POST can crash the HTTP service or execute code in its process.

CVSS severityUnavailable
Unscored
EPSS probability0.44%
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

Stack-based buffer overflow in Tenda F1202 1.2.0.20(408) allows remote authenticated users to execute code via a crafted PPTP request. The fromPptpUserAdd handler passes a user-controlled username to sprintf without a length check when opttype is 1, overflowing stack buffer s__3. Low-privilege access to the network management interface is required; a crafted POST can crash the HTTP service or execute code in its process.

The record

CVE
CVE-2026-9431
Published
May 25, 2026
Updated
May 25, 2026
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
F1202
Classifications
CWE-119, CWE-121, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 25, 2026CVE publishedPublication date reported by the CVE source.
  2. May 25, 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=1.2.0.20(408)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · F1202version=1.2.0.20(408)

Published CVSS scores

8.8VulDB CNACVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
9.0VulDB CNAAV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR
8.8VulDB CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
8.7VulDB CNACVSS: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.

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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-119Memory Corruption
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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