CVE-2026-67236 PUBLISHED

RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login

Assigner: GitHub_M
Reserved: 28.07.2026 Published: 25.09.2026 Updated: 25.09.2026

RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.2.8 and 4.3.2, a successful POST /login caused is_authorized/2 to set an auth cookie containing base64-encoded username:password credentials without HttpOnly, Secure, SameSite, or expiration protections. Because base64 is encoding rather than encryption, an attacker with same-origin cross-site scripting, an HTTP-readable network position, or local access to the browser cookie store could recover the actual login credentials; older browsers that treated an absent SameSite attribute as None also sent the cookie cross-site. This issue is fixed in versions 4.2.8 and 4.3.2.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 8.2

Product Status

Vendor rabbitmq
Product rabbitmq-server
Versions
  • Version >= 4.2.0, < 4.2.8 is affected
  • Version >= 4.3.0, < 4.3.2 is affected

References

Problem Types

  • CWE-312: Cleartext Storage of Sensitive Information CWE