CVE-2025-67716Network attack vector

Altered token issuance via unencoded returnTo

Published Dec 11, 2025 · Updated Dec 11, 2025

OAuth parameter injection in Auth0 Next.js SDK 4.9.0 through 4.12.1 allows attackers to alter authorization requests via returnTo. The withPageAuthRequired helper appends returnTo directly to the configured login URL without URL-encoding it, so delimiters become separate OAuth parameters. Exploitation requires high privileges and user interaction and can cause tokens to be issued with attacker-selected authorization parameters.

CVSS severity5.7
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OAuth parameter injection in Auth0 Next.js SDK 4.9.0 through 4.12.1 allows attackers to alter authorization requests via returnTo. The withPageAuthRequired helper appends returnTo directly to the configured login URL without URL-encoding it, so delimiters become separate OAuth parameters. Exploitation requires high privileges and user interaction and can cause tokens to be issued with attacker-selected authorization parameters.

The record

CVE
CVE-2025-67716
Published
Dec 11, 2025
Updated
Dec 11, 2025
Vendor
Auth0
Product
Auth0 Next.js SDK
Classifications
CWE-184
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 11, 2025Record 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=>= 4.9.0, < 4.13.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Auth0 · Auth0 Next.js SDKversion=>= 4.9.0, < 4.13.0

Published CVSS scores

5.7GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A: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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-184Incomplete List of Disallowed Inputs

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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