CVE-2026-66078: broadcom rabbitmq_server Missing Authorization
Vulnerability summary
CVE-2026-66078 is a medium (CVSS 5.5) Missing Authorization vulnerability in broadcom rabbitmq_server. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 1Timeline
- 25-09-2026PublishedVulnerability first disclosed.
- 29-09-2026Last modifiedVulnerability information updated.
Description
RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.20 and 4.1.11 and 4.2.6, protected tag bypass via bulk-delete. dELETE /api/users/:name refuses to delete users tagged protected (rabbitmgmtwmuser:deleteresource/2 checks isprotecteduser). POST /api/users/bulk-delete iterates the supplied username list and calls rabbitauthbackendinternal:deleteuser/2 directly , that function has no protected-tag check , so the guard is silently An administrator can delete protected-tagged service accounts via the bulk endpoint, bypassing a safeguard the test suite confirms is rabbitmqmanagement enabled Attacker has the administrator tag A protected-tagged user. This issue is fixed in versions 3.13.15 and 4.0.20 and 4.1.11 and 4.2.6.
CVSS metrics
6 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated2.1LowCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- NVDNIST2.1LowCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/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
- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H
EPSS trend
Probability
0.38%
Chance of exploitation in the next 30 days
Percentile
30%
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≥ 3.13.0, < 3.13.15 | ≥ 4.0.0, < 4.0.20 | ≥ 4.1.0, < 4.1.11 | ≥ 4.2.0, < 4.2.6
Debian1 product
- rabbitmq-serverAll versions (No fix recorded) | < 4.3.0-2
Rabbitmq1 product
- rabbitmq-server≥ 3.13.0, < 3.13.15 | ≥ 4.0.0, < 4.0.20 | ≥ 4.1.0, < 4.1.11 | ≥ 4.2.0, < 4.2.6
Ubuntu1 product
- rabbitmq-serverAll versions (No fix recorded)
4 vendors · 4 products
References
6 links- github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-j9m2-hw6x-rqr9X Refsource CONFIRMREPORTExploitThird Party Advisory
- github.com/rabbitmq/rabbitmq-server/commit/e5b890a64b42ec1f79a8e9d735512150cf77479cX Refsource MISCREPORTPatch