Vulnerability · Published Sep 25, 2026 · Assigned by GitHub_M
CVE-2026-67236RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login
High 8.2
In plain English
A high-severity security flaw in rabbitmq-server from rabbitmq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | rabbitmq-server | 4.3.2-1 | DEBIAN-CVE-2026-67236 |
| Ubuntu:22.04:LTS | rabbitmq-server | 3.9.27-0ubuntu0.6 | USN-8933-1 |
| Ubuntu:22.04:LTS | rabbitmq-server | 3.9.27-0ubuntu0.6 | UBUNTU-CVE-2026-67236 |
| Ubuntu:24.04:LTS | rabbitmq-server | 3.12.1-1ubuntu1.7 | UBUNTU-CVE-2026-67236 |
| Ubuntu:24.04:LTS | rabbitmq-server | 3.12.1-1ubuntu1.7 | USN-8933-1 |
| Ubuntu:26.04:LTS | rabbitmq-server | 4.0.5-10ubuntu5.2 | USN-8933-1 |
| Ubuntu:26.04:LTS | rabbitmq-server | 4.0.5-10ubuntu5.2 | UBUNTU-CVE-2026-67236 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| rabbitmq | rabbitmq-server | >= 4.2.0, < 4.2.8>= 4.3.0, < 4.3.2 |
Weakness: CWE-312 · 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
References
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-88vh-gx85-p36m x_refsource_CONFIRM
- https://github.com/rabbitmq/rabbitmq-server/commit/df9e7f4c0afd311a672705f020d301efad355745 x_refsource_MISC
- https://github.com/rabbitmq/rabbitmq-server/commit/edf1fbc7217aaf736955d2e13c9534901a2e0778 x_refsource_MISC
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8 x_refsource_MISC
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2 x_refsource_MISC