CVE-2026-28008Network attack vector

Unauthenticated impersonation via unverified OpenID assertions

Published Aug 13, 2026 · Updated Aug 13, 2026

Broken authentication in miniOrange OAuth Single Sign On – SSO (OAuth Client) 7.0.0 and earlier allows remote attackers to impersonate Steam users. The Steam OpenID callback trusts attacker-controlled openid_claimed_id without sending the assertion to the provider's check_authentication endpoint. Exploitation requires Steam OpenID to be configured and permits login as the WordPress account mapped to the forged identity.

CVSS severity9.8
Critical
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

Broken authentication in miniOrange OAuth Single Sign On – SSO (OAuth Client) 7.0.0 and earlier allows remote attackers to impersonate Steam users. The Steam OpenID callback trusts attacker-controlled openid_claimed_id without sending the assertion to the provider's check_authentication endpoint. Exploitation requires Steam OpenID to be configured and permits login as the WordPress account mapped to the forged identity.

The record

CVE
CVE-2026-28008
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
miniOrange
Product
OAuth Single Sign On – SSO (OAuth Client)
Classifications
CWE-290, CAPEC-151, T1078.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 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 <=7.0.0 changes=[{"at":"7.0.1","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

miniOrange · OAuth Single Sign On – SSO (OAuth Client)version=n/a <=7.0.0 changes=[{"at":"7.0.1","status":"unaffected"}]

Published CVSS scores

9.8PatchstackCVSS:3.1/AV:N/AC:L/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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
CAPEC-151Identity Spoofing
T1078.003Local Accounts

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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