CVE-2026-7748Public exploitNetwork attack vector

Authenticated memory corruption via unbounded FileName copy

Published May 4, 2026 · Updated May 4, 2026

Buffer overflow in TOTOLINK N300RH Firmware 3.2.4-B20220812 allows remote authenticated users to corrupt process memory. The setUpgradeFW handler in /cgi-bin/cstecgi.cgi passes the attacker-controlled FileName value through Var to strcpy without checking its length. A low-privilege web session is required; the published proof of concept supplies a 4,096-byte value, but reliable code execution is not demonstrated.

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

Buffer overflow in TOTOLINK N300RH Firmware 3.2.4-B20220812 allows remote authenticated users to corrupt process memory. The setUpgradeFW handler in /cgi-bin/cstecgi.cgi passes the attacker-controlled FileName value through Var to strcpy without checking its length. A low-privilege web session is required; the published proof of concept supplies a 4,096-byte value, but reliable code execution is not demonstrated.

The record

CVE
CVE-2026-7748
Published
May 4, 2026
Updated
May 4, 2026
Vendor
TOTOLINK
Product
N300RH Firmware
Classifications
CWE-120, CWE-119, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 4, 2026CVE publishedPublication date reported by the CVE source.
  2. May 4, 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=3.2.4-B20220812

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TOTOLINK · N300RH Firmwareversion=3.2.4-B20220812

Published CVSS scores

8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C
7.4VulDBCVSS: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 ('Classic Buffer Overflow')
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
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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