CVE-2025-71403Network attack vectorHinoki check available

Account takeover via trusted-origin validation bypass

Published Aug 1, 2026 · Updated Aug 1, 2026

Open redirect in Better Auth before 1.1.20 allows remote attackers to steal sensitive tokens and take over accounts via callbackURL. The trustedOrigins validation logic accepts crafted absolute URLs and wildcard-domain matches as trusted, then permits them as redirect destinations. Exploitation requires a victim to follow a crafted link; token-bearing redirect endpoints can then send password-reset tokens to an attacker-controlled site.

CVSS severity7.1
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Open redirect in Better Auth before 1.1.20 allows remote attackers to steal sensitive tokens and take over accounts via callbackURL. The trustedOrigins validation logic accepts crafted absolute URLs and wildcard-domain matches as trusted, then permits them as redirect destinations. Exploitation requires a victim to follow a crafted link; token-bearing redirect endpoints can then send password-reset tokens to an attacker-controlled site.

The record

CVE
CVE-2025-71403
Published
Aug 1, 2026
Updated
Aug 1, 2026
Vendor
Better Auth
Product
Better Auth
Classifications
CWE-601, T1204.001
Attack vector
network
Privileges
unauthenticated

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 <1.1.20

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Better Auth · Better Authversion=0 <1.1.20

Published CVSS scores

7.1VulnCheck CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N
7.1VulnCheck CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/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 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-601URL Redirection to Untrusted Site ('Open Redirect')
T1204.001User Execution: Malicious Link

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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