CVE-2026-5676Public exploitNetwork attack vector

Unauthenticated configuration changes via unchecked CGI requests

Published Apr 6, 2026 · Updated Apr 6, 2026

Authentication bypass in TOTOLINK A8000R 5.9c.681_B20180413 allows remote attackers to change router settings without logging in. The setLanguageCfg handler in /cgi-bin/cstecgi.cgi processes attacker-supplied langType values without validating a session cookie or token. A network-reachable management interface is the only gate; a crafted POST request changes device configuration without authentication.

CVSS severity7.3
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in TOTOLINK A8000R 5.9c.681_B20180413 allows remote attackers to change router settings without logging in. The setLanguageCfg handler in /cgi-bin/cstecgi.cgi processes attacker-supplied langType values without validating a session cookie or token. A network-reachable management interface is the only gate; a crafted POST request changes device configuration without authentication.

The record

CVE
CVE-2026-5676
Published
Apr 6, 2026
Updated
Apr 6, 2026
Vendor
TOTOLINK
Product
A8000R
Classifications
CWE-287, CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 6, 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=5.9c.681_B20180413

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

TOTOLINK · A8000Rversion=5.9c.681_B20180413

Published CVSS scores

7.5VulDBAV:N/AC:L/Au:N/C:P/I:P/A:P
7.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
5.5VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
CWE-306Missing Authentication for Critical Function
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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