CVE-2026-8137Public exploitNetwork attack vector

Authenticated code execution via unchecked submit-url copy

Published May 8, 2026 · Updated May 8, 2026

Stack buffer overflow in TOTOLINK X5000R 9.1.0u.6369_B20230113 allows remote authenticated users to execute code via submit-url. The /boafrm/formDdns handler's sub_458E40 function copies the request parameter with strcpy into fixed-size byte_49BB28 without checking its length. Low-privilege network access is the published scoring gate; an oversized value overwrites stack memory, crashing the management service or redirecting execution.

CVSS severity8.8
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in TOTOLINK X5000R 9.1.0u.6369_B20230113 allows remote authenticated users to execute code via submit-url. The /boafrm/formDdns handler's sub_458E40 function copies the request parameter with strcpy into fixed-size byte_49BB28 without checking its length. Low-privilege network access is the published scoring gate; an oversized value overwrites stack memory, crashing the management service or redirecting execution.

The record

CVE
CVE-2026-8137
Published
May 8, 2026
Updated
May 8, 2026
Vendor
TOTOLINK
Product
X5000R
Classifications
CWE-120, CWE-119, T1210
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=9.1.0u.6369_B20230113

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TOTOLINK · X5000Rversion=9.1.0u.6369_B20230113

Published CVSS scores

9.0VulDB CNAAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8VulDB CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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-120Buffer Copy without Checking Size of Input
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1210Exploitation of Remote Services

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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