CVE-2026-19814Public exploitNetwork attack vector

Authenticated memory corruption via unchecked sprintf

Published Aug 14, 2026 · Updated Aug 14, 2026

Stack-based buffer overflow in TOTOLINK A800R 4.1.2cu.5137_B20200730 allows remote authenticated users to corrupt process memory via macAddress. The setMacQos handler in firewall.so passes the request's macAddress parameter to sprintf without a bounds check, overflowing a stack buffer. A valid management session is required, and the public artifact demonstrates the malformed request but does not establish code execution.

CVSS severity8.8
High
EPSS probability0.47%
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 A800R 4.1.2cu.5137_B20200730 allows remote authenticated users to corrupt process memory via macAddress. The setMacQos handler in firewall.so passes the request's macAddress parameter to sprintf without a bounds check, overflowing a stack buffer. A valid management session is required, and the public artifact demonstrates the malformed request but does not establish code execution.

The record

CVE
CVE-2026-19814
Published
Aug 14, 2026
Updated
Aug 14, 2026
Vendor
TOTOLINK
Product
A800R
Classifications
CWE-121, CWE-119
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 14, 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=4.1.2cu.5137_B20200730

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TOTOLINK · A800Rversion=4.1.2cu.5137_B20200730

Published CVSS scores

9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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-121Stack-based Buffer Overflow
CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer

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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