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CVE-2026-50631 Apache Software Foundation CVE debrief

CVE-2026-50631 is a HIGH severity vulnerability in Apache CXF's AbstractOAuthDataProvider. A race condition 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. This can be exploited if a refresh token is leaked and replayed concurrently by multiple attackers or threads. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 to fix this issue.

Vendor
Apache Software Foundation
Product
Apache CXF
CVSS
HIGH 7.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-12
Original CVE updated
2026-08-07
Advisory published
2026-06-12
Advisory updated
2026-08-07

Who should care

Users of Apache CXF, particularly those using versions prior to 4.1.7 or 4.2.2, should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability exists in the AbstractOAuthDataProvider of Apache CXF. When 'recycleRefreshTokens' is set to false, a race condition can occur, allowing multiple valid Access Tokens to be generated from a single Refresh Token if concurrent requests are made. This can lead to unauthorized access if an attacker obtains a refresh token.

Defensive priority

HIGH

Recommended defensive actions

  • Upgrade to Apache CXF version 4.2.2 or 4.1.7.
  • Review and adjust the 'recycleRefreshTokens' setting.
  • Monitor for and restrict concurrent requests using the same Refresh Token.

Evidence notes

The CVE-2026-50631 record and NVD detail provide comprehensive information about this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50631 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50631

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-50631 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50631

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.