CVE-2026-67236
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.2 HIGHCVSS: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/M
- EPSS
- 0.17% probability · 6th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-312
- Affected
- broadcom/rabbitmq server
- Source
- security-advisories@github.com
EPSS moved from 0.1% on 26 September 2026 to 0.2% on 26 October 2026.
References
- https://github.com/rabbitmq/rabbitmq-server/commit/df9e7f4c0afd311a672705f020d301efad355745Patch
- https://github.com/rabbitmq/rabbitmq-server/commit/edf1fbc7217aaf736955d2e13c9534901a2e0778Patch
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8Release Notes
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2Release Notes
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-88vh-gx85-p36mExploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.