RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5, RabbitMQ OAuth credential refresh retains revoked runtime tags. when an existing AMQP connection refreshes from an OAuth token that grants the impersonator tag to a valid same-username token that no longer grants that tag, RabbitMQ updates the OAuth backend implementation (token/scopes/expiry) but leaves the connection's runtime #user.tags unchanged. rabbitaccesscontrol:checkuserid/2 then still honors the stale impersonator tag, so the connection (including newly opened channels) can continue publishing messages with a foreign AMQP userid after that privilege should have been revoked. A fresh connection using the downgraded token correctly refuses the same publish, proving the defect is stale session state rather than the token Limited to connections that once held impersonator and successfully refresh to a downgraded same-username rabbitauthbackendoauth2 (or an equivalent refresh-capable backend that returns tags) is enabled for This issue is fixed in versions 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5.
References
| Link | Resource |
|---|---|
| https://github.com/rabbitmq/rabbitmq-server/commit/5de287d213765ca592ff5848ad2f6b9b98ee6772 | Patch |
| https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5 | Release Notes |
| https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx | Vendor Advisory Mitigation Exploit |
| https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx | Vendor Advisory Mitigation Exploit |
Configurations
Configuration 1 (hide)
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History
16 Oct 2026, 15:38
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Broadcom rabbitmq Server
Broadcom |
|
| CPE | cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 6.5 |
| References | () https://github.com/rabbitmq/rabbitmq-server/commit/5de287d213765ca592ff5848ad2f6b9b98ee6772 - Patch | |
| References | () https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5 - Release Notes | |
| References | () https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx - Vendor Advisory, Mitigation, Exploit |
29 Sep 2026, 20:17
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx - |
25 Sep 2026, 17:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-09-25 17:17
Updated : 2026-10-16 15:38
NVD link : CVE-2026-67420
Mitre link : CVE-2026-67420
CVE.ORG link : CVE-2026-67420
JSON object : View
Products Affected
broadcom
- rabbitmq_server
CWE
CWE-862
Missing Authorization
