CVE-2026-67328Network attack vectorHinoki check available

Account takeover via improperly trusted SSO identities

Published Aug 1, 2026 · Updated Aug 1, 2026

Authentication bypass in Better Auth SSO Plugin before 1.6.21 or 1.7.0-beta.0 through 1.7.0-beta.9 allows attackers to take over accounts. Provider-domain parsers disagree on trusted hosts, deletion leaves reusable linked accounts, and SAML handling omits audience binding and permits active logout URL schemes. Self-service provider registration and implicit account linking expose the first three paths; the XSS path requires single logout and victim interaction.

CVSS severity8.6
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Authentication bypass in Better Auth SSO Plugin before 1.6.21 or 1.7.0-beta.0 through 1.7.0-beta.9 allows attackers to take over accounts. Provider-domain parsers disagree on trusted hosts, deletion leaves reusable linked accounts, and SAML handling omits audience binding and permits active logout URL schemes. Self-service provider registration and implicit account linking expose the first three paths; the XSS path requires single logout and victim interaction.

The record

CVE
CVE-2026-67328
Published
Aug 1, 2026
Updated
Aug 1, 2026
Vendor
Better Auth
Product
Better Auth SSO Plugin
Classifications
CWE-347, CWE-459, CWE-287, CWE-345, CWE-79, T1078, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 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=0 <1.6.21
  2. Affected versionversion=1.7.0-beta.0 <1.7.0-beta.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Better Auth · Better Auth SSO Pluginversion=0 <1.6.21; version=1.7.0-beta.0 <1.7.0-beta.10

Published CVSS scores

8.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
8.6VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
CWE-459Incomplete Cleanup
CWE-287Improper Authentication
CWE-345Insufficient Verification of Data Authenticity
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1078Valid Accounts
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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