CVE-2026-79911Public exploitNetwork attack vector

Unauthenticated code execution via unchecked Hostname copy

Published Aug 25, 2026 · Updated Aug 25, 2026

Stack-based buffer overflow in TOTOLINK N600R 4.3.0cu.7647_B20210106 allows remote attackers to execute code via a crafted Hostname. The setSystemConfig handler in /cgi-bin/cstecgi.cgi passes the HTTP Hostname value to strcpy, copying it into a fixed-size stack buffer without a length check. No authentication or user interaction is required; an oversized POST can overwrite the saved return address and execute code or crash and reboot the router.

CVSS severity10.0
Critical
EPSS probability0.64%
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 TOTOLINK N600R 4.3.0cu.7647_B20210106 allows remote attackers to execute code via a crafted Hostname. The setSystemConfig handler in /cgi-bin/cstecgi.cgi passes the HTTP Hostname value to strcpy, copying it into a fixed-size stack buffer without a length check. No authentication or user interaction is required; an oversized POST can overwrite the saved return address and execute code or crash and reboot the router.

The record

CVE
CVE-2026-79911
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
TOTOLINK
Product
N600R
Classifications
CWE-119, CWE-121, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 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=4.3.0cu.7647_B20210106

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

TOTOLINK · N600Rversion=4.3.0cu.7647_B20210106

Published CVSS scores

10.0VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
10.0VulDBAV:N/AC:L/Au:N/C:C/I:C/A:C
9.3VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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
Privilegesunauthenticated
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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