CVE-2026-50631 — Apache CXF: OAuth2: TOCTOU Race Condition in Refresh Token Processing

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
Apache Software Foundation / Apache CXF	affected 4.2.0 before 4.2.2; affected 4.0.0 before 4.1.7; affected 0 before 3.6.12

CWE

CWE-367

References

https://lists.apache.org/thread/s83t3x4r626o9h8rt0ryr1w7w53l1vv8

ADP enrichment

CVE

No English description supplied.

http://www.openwall.com/lists/oss-security/2026/06/11/8

CISA-ADP

No English description supplied.

No references supplied.