SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-67420

RabbitMQ is a messaging and streaming broker.

LOW 2.3EPSS 0.27%

Does this matter?

Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own.

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newly opened channels) can continue publishing messages with a foreign AMQP userid after that privilege should have been revoked.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

CVSS 4.0
2.3 LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.27% probability · 19th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-862
Affected
broadcom/rabbitmq server
Source
security-advisories@github.com
EPSS trend
0%3%5%26 September 2026: 0.24%26 October 2026: 0.27%26 September 202626 October 2026

EPSS moved from 0.2% on 26 September 2026 to 0.3% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.