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CxfApplication · Apache

CVE-2026-50631

HIGH · 7.4 CVSS v3.1 Published 2026-06-12
Fix available
A fix is available. Upgrade to 4.1.7 / 4.2.2 or later.
See remediation →
83/100
Remediation priority · High
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 race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypass single-use semantics and generate multiple valid Access Tokens, when 'recycleRefreshTokens' is set to false. A leaked refresh token can be replayed concurrently by multiple attackers or threads. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue.

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 · high confidence

A race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypass single-use semantics and generate multiple valid Access Tokens when 'recycleRefreshTokens' is set to false. The vulnerability occurs because the refresh token validation and invalidation are not performed atomically, allowing multiple threads to obtain valid access tokens before the token is marked as used.

MitigationUpgrade to versions 4.2.2 or 4.1.7 which contain the fix for this race condition. Until upgraded, monitor for suspicious concurrent token refresh attempts using the same credentials.

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
CxfApplication
Affected:< 4.1.7>= 4.2.0, < 4.2.2

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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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. Identify Apache CXF version
    Locate the CXF JAR files in your application (typically in WEB-INF/lib or classpath) or check your build configuration (pom.xml, build.gradle) for the cxf-core or cxf-rt-oauth2 artifact version
    Affected if The installed version is < 4.1.7 OR >= 4.2.0 and < 4.2.2
  2. Verify OAuth2 provider is in use
    Search your codebase or configuration for classes extending AbstractOAuthDataProvider or configuring OAuth2 providers, such as looking for XML configuration files with OAuth2 provider beans or Java-based OAuth provider configuration
    Affected if Your application uses Apache CXF's OAuth2 implementation with AbstractOAuthDataProvider
  3. Check recycleRefreshTokens configuration
    Examine your OAuth2 provider configuration (often in application context XML files or configuration properties) for the recycleRefreshTokens setting
    Affected if recycleRefreshTokens is explicitly set to false or not set (defaults to false in vulnerable configurations)
  4. Inspect token refresh endpoint exposure
    Review your web service configuration to confirm the /oauth/token or refresh endpoint is exposed and accessible
    Affected if Your application exposes an OAuth2 token refresh endpoint that accepts refresh tokens

You are affected if you run a vulnerable CXF version (4.2.0-4.2.1 or <4.1.7) with OAuth2 using AbstractOAuthDataProvider where recycleRefreshTokens is set to false.

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.

dbcve · scoped
Upgrade available Upgrade to 4.1.7 / 4.2.2 or later
Fixed in 4.1.74.2.2
Interim mitigation

Upgrade to versions 4.2.2 or 4.1.7 which contain the fix for this race condition. Until upgraded, monitor for suspicious concurrent token refresh attempts using the same credentials.

Recommended fix High confidence

4.2.2 or 4.1.7 (depending on current version branch)

  1. Identify the current CXF version in use by checking project dependencies (Maven pom.xml, Gradle build.gradle, or library management system)
  2. Determine which upgrade path applies: if current version is < 4.1.7, upgrade to 4.1.7; if current version is >= 4.2.0 and < 4.2.2, upgrade to 4.2.2
  3. Update the dependency version in your build configuration (e.g., change org.apache.cxf:cxf-rt-oauth2 to version 4.1.7 or 4.2.2)
  4. Run build and automated tests to verify compatibility with the new version
  5. Deploy the upgraded version to production after validation in staging
Caveat Security point releases typically have minimal breaking changes, but review CXF 4.2.2 and 4.1.7 release notes for any API or behavioral changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Cxf Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,970
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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-2026-50631 in production — separate from our analysis above.

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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
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