Medium severity · published Sep 25, 2026
CVE-2026-67236
RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login
6.5
CVSS
0.2%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 6% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RA
rabbitmq-server · rabbitmq
>= 4.2.0, < 4.2.8; >= 4.3.0, < 4.3.2 · source: vendor
RS
Rabbitmq Server · Broadcom
4.2.0 before 4.2.8; 4.3.0 before 4.3.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-67236
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-67236
x_refsource_CONFIRM
https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-88vh-gx85-p36m
x_refsource_MISC
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
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