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Fencer Vulns
medium 6.5

CVE-2026-67419 json

RabbitMQ: Consecutive topic wildcards cause combinatorial routing work

published 2026-09-25 44 d ago modified 2026-10-17 23 d ago also BIT-rabbitmq-2026-67419 , EUVD-2026-87243 , GHSA-h964-v5mf-22cq

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

RabbitMQ is a messaging and streaming broker. Prior to 4.3.5, an authenticated user who can bind a queue to a topic exchange and publish to it can use consecutive # segments in a binding key to make both topic matchers revisit the same trie-node and routing-key-suffix states without memoization. The matcher materializes duplicate destinations before deduplication, causing combinatorial CPU work and memory pressure that can disrupt routing for all tenants. This vulnerability is fixed in 4.3.5.

Patch / fix

  • bitnami rabbitmq 4.3.5
  • pivotal_software rabbitmq 4.3.5
  • vmware rabbitmq 4.3.5
  • rabbitmq-server Debian 14 4.3.6-1

debian advisories DEBIAN-CVE-2026-67419

  • 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-104925

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-2026-67419 updated cvss 6.5

rabbitmq-server: rabbitmq-server: Denial of Service via consecutive wildcards in topic binding keys

  • Red Hat Hardened Images rabbitmq-server4.2 4.2.9-0.2.hum1
    affected: workaround, no fix planned “Will not fix”
  • Red Hat OpenStack Platform 13 (Queens) rabbitmq-server Red Hat OpenStack Platform 16.2 rabbitmq-server Red Hat OpenStack Platform 17.1 rabbitmq-server
    affected: workaround, no fix planned “Out of support scope”
  • 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 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
partial
Assessed
44 d ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-h964-v5mf-22cq referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami rabbitmq
<4.3.5
4.3.5

Affected products

  • rabbitmq rabbitmq-server

Classification

Weakness
  • CWE-407 Inefficient Algorithmic Complexity
  • CWE-1333 Inefficient Regular Expression Complexity

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.