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KeycloakApplication · Redhat

CVE-2025-8419

MEDIUM · 5.3 CVSS v3.1 Published 2025-08-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability was found in Keycloak-services. Special characters used during e-mail registration may perform SMTP Injection and unexpectedly send short unwanted e-mails. The email is limited to 64 characters (limited local part of the email), so the attack is limited to very shorts emails (subject and little data, the example is 60 chars). This flaw's only direct consequence is an unsolicited email being sent from the Keycloak server. However, this action could be a precursor for more sophisticated attacks.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

SMTP injection vulnerability in Keycloak-services allows attackers to inject special characters during e-mail registration, enabling unauthorized short emails (up to 60 chars) to be sent from the Keycloak server. The attack is constrained by a 64-character limit on the email local part.

MitigationImplement strict input validation and sanitization of special characters in email registration fields to block SMTP injection attempts.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
KeycloakApplication
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Keycloak deployment
    Identify if Keycloak is running in your environment by checking for Keycloak services, containers, or processes. Look for keycloak-related processes or the typical port 8080/8443 listeners.
    Affected if Keycloak is deployed and handling user registration or email workflows.
  2. Verify email registration is enabled
    Review Keycloak realm settings to determine if user registration or email-based workflows are enabled. Check authentication flows that include email-related steps.
    Affected if Email registration or any email-sending user workflows are active in the Keycloak realm.
  3. Inspect email provider configuration
    Locate the Keycloak email configuration file or admin console settings. Check for the SMTP host settings, typically found under Realm Settings > Email in the admin console or in standalone.xml/domain.xml configuration files.
    Affected if SMTP configuration exists and is actively used for sending emails from Keycloak.
  4. Review email sending logs
    Examine Keycloak server logs and mail server logs for unusual email activity. Look for emails with unexpected headers, multiple recipients, or emails sent in rapid succession from registration events.
    Affected if Emails are being sent through Keycloak and logs are available for review.
  5. Check for input validation gaps
    Assess whether the email field in registration forms accepts and processes special characters without strict validation. This may require code review of custom themes or extensions or testing with characters like newlines, carriage returns, or semicolons.
    Affected if Special characters can be submitted in email fields during registration without being rejected.

Your environment is affected if Keycloak is running with email registration or email-sending capabilities enabled and the email input lacks strict validation of special characters.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement strict input validation and sanitization of special characters in email registration fields to block SMTP injection attempts.

Fix this in Keycloak Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-8419 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data