Expired-token authentication via float expiry claim
Published Sep 25, 2026 · Updated Sep 25, 2026
Authentication bypass in RabbitMQ Server 4.2.0 through 4.2.8 and 4.3.0 through 4.3.2 allows remote attackers to reuse expired OAuth2 tokens. validate_token_expiry/1 and expiry_timestamp/1 check only integer exp values, so floating-point values fall through without expiry validation or a disconnect timer. Exploitation requires the OAuth2 backend, an identity provider that emits a floating-point exp claim, and possession of a previously valid signed token.
Summary
What happened
Authentication bypass in RabbitMQ Server 4.2.0 through 4.2.8 and 4.3.0 through 4.3.2 allows remote attackers to reuse expired OAuth2 tokens. validate_token_expiry/1 and expiry_timestamp/1 check only integer exp values, so floating-point values fall through without expiry validation or a disconnect timer. Exploitation requires the OAuth2 backend, an identity provider that emits a floating-point exp claim, and possession of a previously valid signed token.
The record
- CVE
- CVE-2026-67242
- Published
- Sep 25, 2026
- Updated
- Sep 25, 2026
- Vendor
- RabbitMQ
- Product
- RabbitMQ Server
- Classifications
- CWE-613, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 25, 2026CVE publishedPublication date reported by the CVE source.
- Sep 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 4.2.0, < 4.2.9
- Affected versionversion=>= 4.3.0, < 4.3.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
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