CVE-2026-67407: broadcom rabbitmq_server Missing Authorization
Vulnerability summary
CVE-2026-67407 is a high (CVSS 7.1) Missing Authorization vulnerability in broadcom rabbitmq_server. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 12.5% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 1Timeline
- 25-09-2026PublishedVulnerability first disclosed.
- 25-09-2026Last modifiedVulnerability information updated.
Description
RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.3.3 and 4.2.9 and 4.1.14 and 4.0.23, Incomplete fix for CVE-2026-44838: escaperegexchar/1 does not escape -, leaving room for an MQTT topic permission bypass. the CVE-2026-44838 fix made expandtopicpermission/2 escape regex metacharacters in expanded topic-permission variables (escaperegex(V)), but escaperegexchar/1 escapes \ ^ $ . | ? + ( ) [ ] { } and omits -. When a topic permission template places {clientid} inside a [...] character class A low-privileged authenticated MQTT user controlling its clientid can broaden topic authorization (read and write) when templates embed {clientid} in a [...] This issue is fixed in versions 4.3.3 and 4.2.9 and 4.1.14 and 4.0.23.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.1MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N
- OSV · DebianEcosystem advisory · calculated5.1MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/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
- NVDNIST5.1MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/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 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
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundRabbitmq Server
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Broadcom1 product
- rabbitmq_server≥ 4.0.0, < 4.0.23 | ≥ 4.1.0, < 4.1.14 | ≥ 4.2.0, < 4.2.9 | ≥ 4.3.0, < 4.3.3
Debian1 product
- rabbitmq-serverAll versions (No fix recorded) | < 4.3.6-1
Rabbitmq1 product
- rabbitmq-server≥ 4.3.2, < 4.3.3 | ≥ 4.2.0, < 4.2.9 | ≥ 4.1.0, < 4.1.14 | ≥ 4.0.0, < 4.0.23
Ubuntu1 product
- rabbitmq-serverAll versions (No fix recorded)
4 vendors · 4 products
References
6 links- github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q46v-hrvq-hp24X Refsource CONFIRMREPORTVendor AdvisoryExploitMitigation