CVE-2026-67420
RabbitMQ OAuth credential refresh retains revoked runtime tags
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newly opened channels) can continue publishing messages with a foreign AMQP userid after that privilege should have been revoked.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.
INFO
Published Date :
Sept. 25, 2026, 5:17 p.m.
Last Modified :
Oct. 16, 2026, 3:38 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Update RabbitMQ to versions 3.13.19, 4.0.24, 4.1.15, 4.2.10, or 4.3.5.
- Restart RabbitMQ service after updating.
- Verify OAuth token refresh behavior.
- Monitor RabbitMQ security logs.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-67420.
| URL | 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 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-67420 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-67420
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-67420 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-67420 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Oct. 16, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 4.0.0 up to (excluding) 4.0.24 *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 4.1.0 up to (excluding) 4.1.15 *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 4.2.0 up to (excluding) 4.2.10 *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 4.3.0 up to (excluding) 4.3.5 *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 3.13.0 up to (excluding) 3.13.19 Added Reference Type GitHub, Inc.: https://github.com/rabbitmq/rabbitmq-server/commit/5de287d213765ca592ff5848ad2f6b9b98ee6772 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx Types: Exploit, Mitigation, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx Types: Exploit, Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 29, 2026
Action Type Old Value New Value Added Reference https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx Added SSVC {'id': 'CVE-2026-67420', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-29T19:31:38.545817Z'} -
New CVE Received by [email protected]
Sep. 25, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 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 Added CWE CWE-862 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/67xxx/CVE-2026-67420.json">CVE-2026-67420</a> Added Reference https://github.com/rabbitmq/rabbitmq-server/commit/5de287d213765ca592ff5848ad2f6b9b98ee6772 Added Reference https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5 Added Reference https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx