6.5

CVE-2026-67420: broadcom rabbitmq_server Missing Authorization

CVSS: 6.5v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-67420DEBIAN-CVE-2026-67420
Published 25-09-2026Last modified 29-09-2026
Open JSON

Vulnerability summary

CVE-2026-67420 is a medium (CVSS 6.5) Missing Authorization vulnerability in broadcom rabbitmq_server. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.3% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
36/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.23%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 1
RHSA-2026:67552

Timeline

  1. 25-09-2026
    PublishedVulnerability first disclosed.
  2. 29-09-2026
    Last modifiedVulnerability information updated.

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newly opened channels) can continue publishing messages with a foreign AMQP userid after that privilege should have been revoked.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

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.23%

Chance of exploitation in the next 30 days

Percentile

13%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

26-09-202619-10-2026
EPSS score
0.23%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Rabbitmq Server

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Broadcom1 product
  • rabbitmq_server≥ 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
Debian1 product
  • rabbitmq-serverAll versions (No fix recorded) | < 4.3.6-1
Rabbitmq1 product
  • rabbitmq-server≥ 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
Ubuntu1 product
  • rabbitmq-serverAll versions (No fix recorded)

4 vendors · 4 products

References

6 links