CVE-2026-67234Network attack vectorHinoki check available

Stale authentication preference via malformed cookie deletion

Published Sep 25, 2026 · Updated Sep 25, 2026

Improper cookie validation in RabbitMQ Server 4.2.0 through 4.2.7 and 4.3.0 through 4.3.1 allows remote attackers to retain stale login preferences. The get_auth_mechanism/1 path passes the preference atom to term_to_binary/1 when clearing its cookie, creating a non-ASCII name that browsers reject instead of deleting the intended cookie. Reachability requires the management UI and browser interaction; the consequence is limited to a prior authentication-mechanism preference persisting across logout and login cycles.

CVSS severity2.3
Low
EPSS probability0.56%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

Improper cookie validation in RabbitMQ Server 4.2.0 through 4.2.7 and 4.3.0 through 4.3.1 allows remote attackers to retain stale login preferences. The get_auth_mechanism/1 path passes the preference atom to term_to_binary/1 when clearing its cookie, creating a non-ASCII name that browsers reject instead of deleting the intended cookie. Reachability requires the management UI and browser interaction; the consequence is limited to a prior authentication-mechanism preference persisting across logout and login cycles.

The record

CVE
CVE-2026-67234
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
RabbitMQ
Product
RabbitMQ Server
Classifications
CWE-20
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 4.2.0, < 4.2.8
  2. Affected versionversion=>= 4.3.0, < 4.3.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

RabbitMQ · RabbitMQ Serverversion=>= 4.2.0, < 4.2.8; version=>= 4.3.0, < 4.3.2

Published CVSS scores

2.3GitHubCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started