RabbitMQ: LDAP DN injection via unescaped substitution

Summary

CVE	CVE-2026-67223
State	PUBLISHED
Assigner	GitHub_M
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-09-25 17:17:10 UTC
Updated	2026-10-15 19:54:50 UTC
Description	RabbitMQ is a messaging and streaming broker. The advisory establishes affected 3.13, 4.0, 4.1, 4.2, and 4.3 maintenance lines but contains conflicting first-fixed versions for the 3.13, 4.0, and 4.1 lines. fill/2 substitutes ${username} into user_dn_pattern without RFC 4514 DN escaping, allowing a crafted username to alter the LDAP bind DN and potentially select a different directory entry. Exploitation requires rabbitmq_auth_backend_ldap with a user_dn_pattern containing ${username}, a directory layout in which the injected suffix resolves usefully, and a password valid for the resulting DN. The advisory body identifies 3.13.15, 4.0.20, 4.1.11, 4.2.9, and 4.3.3 as fixed, while structured metadata identifies 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3. No fixed-version assertion is certifiable until a curator resolves this conflict.

Risk And Classification

Primary CVSS: v4.0 6.3 MEDIUM from [email protected]

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/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

EPSS: 0.003500000 probability, percentile 0.261150000 (date 2026-09-29)

Problem Types: CWE-90 | CWE-90 CWE-90: Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')

Version	Source	Type	Score	Severity	Vector
4.0	[email protected]	Secondary	6.3	MEDIUM	`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/C...`
4.0	CNA	DECLARED	6.3	MEDIUM	`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`
3.1	[email protected]	Primary	7.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N`

CVSS v4.0 Breakdown

Attack Vector

Network

Attack Complexity

High

Attack Requirements

Present

Privileges Required

None

User Interaction

None

Confidentiality

None

Integrity

Low

Availability

None

Sub Conf.

None

Sub Integrity

None

Sub Availability

None

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/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

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

NVD Known Affected Configurations (CPE 2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Application	Broadcom	Rabbitmq Server	All	All	All	All

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Rabbitmq	Rabbitmq-server	affected >= 3.13.0, < 3.13.18	Not specified
CNA	Rabbitmq	Rabbitmq-server	affected >= 4.0.0, < 4.0.23	Not specified
CNA	Rabbitmq	Rabbitmq-server	affected >= 4.1.0, < 4.1.14	Not specified
CNA	Rabbitmq	Rabbitmq-server	affected >= 4.2.0, < 4.2.9	Not specified
CNA	Rabbitmq	Rabbitmq-server	affected >= 4.3.0, < 4.3.3	Not specified

References

Reference	Source	Link	Tags
github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9	[email protected]	github.com	Release Notes
github.com/rabbitmq/rabbitmq-server/commit/b54056e59b7fd3a2d7f07dfaba95f...	[email protected]	github.com	Patch
github.com/rabbitmq/rabbitmq-server/commit/ad3ca47accd313a4a0dbcbbe17bf6...	[email protected]	github.com	Patch
github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3	[email protected]	github.com	Release Notes
github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-9x7r-g78c-5835	[email protected]	github.com	Vendor Advisory
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

There are currently no legacy QID mappings associated with this CVE.