RabbitMQ OAuth credential refresh retains revoked runtime tags

Summary

CVE	CVE-2026-67420
State	PUBLISHED
Assigner	GitHub_M
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-09-25 17:17:13 UTC
Updated	2026-10-16 15:38:45 UTC
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newly opened channels) can continue publishing messages with a foreign AMQP userid after that privilege should have been revoked.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.

Risk And Classification

Primary CVSS: v4.0 2.3 LOW from [email protected]

CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.002380000 probability, percentile 0.133710000 (date 2026-09-29)

Problem Types: CWE-862 | CWE-862 CWE-862: Missing Authorization

Version	Source	Type	Score	Severity	Vector
4.0	[email protected]	Secondary	2.3	LOW	`CVSS: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/C...`
4.0	CNA	DECLARED	2.3	LOW	`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`
3.1	[email protected]	Primary	6.5	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`

CVSS v4.0 Breakdown

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

Present

Privileges Required

Low

User Interaction

None

Confidentiality

Low

Integrity

Low

Availability

None

Sub Conf.

None

Sub Integrity

None

Sub Availability

None

CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

NVD Known Affected Configurations (CPE 2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Application	Broadcom	Rabbitmq Server	All	All	All	All

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Rabbitmq	Rabbitmq-server	affected >= 3.13.0, < 3.13.19	Not specified
CNA	Rabbitmq	Rabbitmq-server	affected >= 4.0.0, < 4.0.24	Not specified
CNA	Rabbitmq	Rabbitmq-server	affected >= 4.1.0, < 4.1.15	Not specified
CNA	Rabbitmq	Rabbitmq-server	affected >= 4.2.0, < 4.2.10	Not specified
CNA	Rabbitmq	Rabbitmq-server	affected >= 4.3.0, < 4.3.5	Not specified

References

Reference	Source	Link	Tags
github.com/rabbitmq/rabbitmq-server/commit/5de287d213765ca592ff5848ad2f6...	[email protected]	github.com	Patch
github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx	134c704f-9b21-4f2e-91b3-4a467353bcc0	github.com	Vendor Advisory, Mitigation, Exploit
github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5	[email protected]	github.com	Release Notes
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

There are currently no legacy QID mappings associated with this CVE.