CVE-2026-82228Network attack vector

Unauthenticated two-factor authentication bypass

Published Aug 31, 2026 · Updated Sep 1, 2026

Authentication bypass in SiteGround Security Optimizer 1.6.6 and earlier allows remote attackers to bypass two-factor authentication. Neither the CNA record nor its Patchstack reference discloses the request, function, or spoofed identity data that causes the bypass. Exploitation requires network access and an undisclosed higher-complexity condition; public sources do not define the resulting account access.

CVSS severity8.1
High
EPSS probability0.23%
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 SiteGround Security Optimizer 1.6.6 and earlier allows remote attackers to bypass two-factor authentication. Neither the CNA record nor its Patchstack reference discloses the request, function, or spoofed identity data that causes the bypass. Exploitation requires network access and an undisclosed higher-complexity condition; public sources do not define the resulting account access.

The record

CVE
CVE-2026-82228
Published
Aug 31, 2026
Updated
Sep 1, 2026
Vendor
SiteGround
Product
Security Optimizer
Classifications
CWE-290, CAPEC-151, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 1, 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=n/a <=1.6.6 changes=[{"at":"1.6.7","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SiteGround · Security Optimizerversion=n/a <=1.6.6 changes=[{"at":"1.6.7","status":"unaffected"}]

Published CVSS scores

8.1PatchstackCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
CAPEC-151Identity Spoofing
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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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