CVE-2026-67234

low

Description

RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.2.8 and 4.3.2, get_auth_mechanism/1 used term_to_binary/1 on the strict_auth_mechanism or preferred_auth_mechanism atom when clearing the corresponding cookie, producing a non-ASCII cookie name that violates RFC 6265 and can prevent the browser from deleting the preference. The issue is not directly exploitable for code execution or data exfiltration; its security relevance is limited to stale authentication-mechanism preferences persisting across logout and login cycles. This issue is fixed in versions 4.2.8 and 4.3.2.

References

https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q286-p3m9-j69f

https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2

https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8

https://github.com/rabbitmq/rabbitmq-server/commit/baac0aaf170efeb4f124ee36b8417274fa8dcc1a

https://github.com/rabbitmq/rabbitmq-server/commit/149cb59d618cefa83c6deb02dbbb1e8a7a2bc968

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-87146

Details

Source: Mitre, NVD

Published: 2026-09-25

Updated: 2026-09-28

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

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

Severity: Critical

CVSS v4

Base Score: 2.3

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

Severity: Low

EPSS

EPSS: 0.00561