CVE-2026-8138Public exploitNetwork attack vector

Authenticated code execution via unbounded startIp parsing

Published May 8, 2026 · Updated May 8, 2026

Stack-based buffer overflow in Tenda CX12L 16.03.53.12 allows remote authenticated users to corrupt memory through a crafted PPTP request. In formSetPPTPServer, sscanf parses the startIp parameter with an unbounded %s conversion into a fixed-size stack buffer. CNA scoring requires low privileges; successful corruption can crash the web process or redirect execution on the router.

CVSS severity8.8
High
EPSS probability0.57%
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 CX12L 16.03.53.12 allows remote authenticated users to corrupt memory through a crafted PPTP request. In formSetPPTPServer, sscanf parses the startIp parameter with an unbounded %s conversion into a fixed-size stack buffer. CNA scoring requires low privileges; successful corruption can crash the web process or redirect execution on the router.

The record

CVE
CVE-2026-8138
Published
May 8, 2026
Updated
May 8, 2026
Vendor
Shenzhen Tenda Technology Co., Ltd.
Product
CX12L
Classifications
CWE-119, CWE-121, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 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=16.03.53.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Shenzhen Tenda Technology Co., Ltd. · CX12Lversion=16.03.53.12

Published CVSS scores

8.8VulDB CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0VulDB CNAAV:N/AC:L/Au:S/C:C/I:C/A:C
7.4VulDB 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.

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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