CVE-2026-50631

Apache CXF: OAuth2: TOCTOU Race Condition in Refresh Token Processing

State: Published
Severity: 7.4 High
Published: Jun 12, 2026
Updated: Aug 7, 2026
Reserved: Jun 5, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.4 High	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N	CISA-ADP

Weaknesses

CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

Affected Products

Product	Versions
Apache CXFApache Software Foundation	4.2.0 to before 4.2.2Affected 4.0.0 to before 4.1.7Affected before 3.6.12Affected

References

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