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 products
broadcom: rabbitmq server
References5
- github.com/rabbitmq/rabbitmq-server/commit/df9e7f4c0afd311a6727… Patch
- github.com/rabbitmq/rabbitmq-server/commit/edf1fbc7217aaf736955… Patch
- github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-88… ExploitThird Party Advisory
- github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8 Release Notes
- github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2 Release Notes
Metrics
- CVSS 3.1
-
6.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - CVSS 4.0
-
8.2
HIGH
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 6 · as of 9 November 2026
- CWE
- CWE-312
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.