Vulnerability Details CVE-2026-66070
RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6, match_origin/1 returned the bare reflected Origin and allowed credentials even when the wildcard "" was configured, so the response echoed the attacker's origin together with Access-Control-Allow-Credentials. The affected code is rabbit_mgmt_cors.erl. When the management plugin is configured with a wildcard CORS origin (cors_allow_origins = ""), the handler reflects the request Origin back in Access-Control-Allow-Origin and also sends Access-Control-Allow-Credentials: true. A malicious web page that a signed-in administrator visits can then use that administrator's cached HTTP Basic credentials to issue authenticated, state-changing requests to the management API. Preconditions include The management plugin is configured with the wildcard cors_allow_origins = "*", which is an explicit operator misconfiguration A target administrator has a cached HTTP Basic-auth session in the browser. This issue is fixed in versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.004
EPSS Ranking 34.2%
CVSS Severity
CVSS v3 Score 8.8
Products affected by CVE-2026-66070
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.0
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.1
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.10
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.11
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.12
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.13
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.14
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.15
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.16
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.2
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.3
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.4
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.5
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.6
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.7
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.8
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cpe:2.3:a:broadcom:rabbitmq_server:3.13.9
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.0
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.1
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.2
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.3
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.4
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.5