CyberSecBulletin
CVE-2026-67404NVD status: Analyzed

rabbitmq-server: Improper Certificate Validation

Published Updated By the CyberSecBulletin desk

CVE-2026-67404 is a high-severity improper certificate validation vulnerability in rabbitmq-server from Rabbitmq, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected rabbitmq-server versions: >= 3.13.0, < 3.13.15; >= 4.0.0, < 4.0.20; >= 4.1.0, < 4.1.11, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.2% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of rabbitmq-server you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Rabbitmqrabbitmq-server>= 3.13.0, < 3.13.15; >= 4.0.0, < 4.0.20; >= 4.1.0, < 4.1.11; >= 4.2.0, < 4.2.6Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.09.2CriticalCNA (github.com)
CVSS 3.17.4HighNVD

Official description

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, When no CA bundle is available, ssl_options/1 falls back to [{verify, verify_none}] with no warning. An attacker in a man-in-the-middle position can forge the JWKS response, which leads the broker to accept arbitrary JWTs. Preconditions include The OAuth2 plugin must be in use with no cacertfile configured and the OS CA bundle empty or unreadable (for example, in a minimal container), and the attacker must hold a network man-in-the-middle position.. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

How developers prevent this class of flaw

  • Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
  • If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.

More Improper Certificate Validation vulnerabilities (CWE-295)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in rabbitmq-server

All rabbitmq-server vulnerabilities

Recent Improper Certificate Validation vulnerabilities

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