All vulnerabilities
CVE-2026-67420GHSA-86fm-44m9-rqjx

rabbitmq-server: RabbitMQ OAuth credential refresh retains revoked runtime tags

rabbitmq rabbitmq-server
CVSS
2.3Low
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 29 Sep 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.23%Chance of exploitation activity in the next 30 days, higher than 13% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published25 Sep 2026Updated 29 Sep 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

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newly opened channels) can continue publishing messages with a foreign AMQP userid after that privilege should have been revoked.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.

Text from CVE List

Affected versions 5

  • rabbitmq-serveraffected: >= 3.13.0, < 3.13.19CVE List
  • rabbitmq-serveraffected: >= 4.0.0, < 4.0.24CVE List
  • rabbitmq-serveraffected: >= 4.1.0, < 4.1.15CVE List
  • rabbitmq-serveraffected: >= 4.2.0, < 4.2.10CVE List
  • rabbitmq-serveraffected: >= 4.3.0, < 4.3.5CVE List

References 3