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Fencer Vulns
medium 6.5

CVE-2026-67420 json

RabbitMQ OAuth credential refresh retains revoked runtime tags

published 2026-09-25 45 d ago modified 2026-10-17 23 d ago also BIT-rabbitmq-2026-67420 , EUVD-2026-87244 , GHSA-86fm-44m9-rqjx

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

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newly opened channels) can continue publishing messages with a foreign AMQP userid after that privilege should have been revoked.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

Patch / fix

  • bitnami rabbitmq 3.13.19, 4.0.24, 4.1.15, 4.2.10, 4.3.5
  • pivotal_software rabbitmq 3.13.19, 4.0.24, 4.1.15, 4.2.10, 4.3.5
  • vmware rabbitmq 3.13.19, 4.0.24, 4.1.15, 4.2.10, 4.3.5
  • rabbitmq-server Debian 14 4.3.6-1

debian advisories DEBIAN-CVE-2026-67420

  • rabbitmq-server4.3 hummingbird 1 4.3.6-1.hum1

red hat advisories RHSA-2026:67552

  • rabbitmq-server Azure Linux 3.0 3.13.7-10

azure linux advisories AZL-105311

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-67420 updated cvss 3.1

rabbitmq-server: rabbitmq-server: Unauthorized user impersonation via stale OAuth token refresh

  • Red Hat Hardened Images rabbitmq-server4.2 4.2.9-0.2.hum1 Red Hat OpenStack Platform 18.0 rabbitmq-server
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images rabbitmq-server4.3 4.3.6-1.hum1
    fixed: vendor fix RHSA-2026:67552
  • Red Hat OpenStack Platform 13 (Queens) rabbitmq-server Red Hat OpenStack Platform 16.2 rabbitmq-server Red Hat OpenStack Platform 17.1 rabbitmq-server
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
40 d ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-86fm-44m9-rqjx referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 2.3 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
CNA 4.0 2.3 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
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
bitnami rabbitmq
>=3.13.0, <3.13.19
>=4.0.0, <4.0.24
>=4.1.0, <4.1.15
>=4.2.0, <4.2.10
>=4.3.0, <4.3.5
3.13.19
4.0.24
4.1.15
4.2.10
4.3.5

Affected products

  • rabbitmq rabbitmq-server

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.