CVE-2026-66071: RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1, Atom exhaustion: OAuth2 JWT tag: scope…

PriorityP337medium6.5CVSS 3.1

AVNACLPRLUINSUCNINAH

EPSS

0.47%

40.1th percentile

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1, Atom exhaustion: OAuth2 JWT tag: scope values. extractscopes/1 parses scopes of the form .tag: and calls rabbitdatacoercion:toatom() to convert to a tag atom. The token signature is verified first, so the attacker cannot forge scopes , but in IdP configurations where scope content is user-influenced, each login with a novel tag value leaks one In deployments where users can influence the scopes included in their IdP-issued JWT rabbitmqauthbackendoauth2 enabled IdP permits attacker-influenced scope values in signed tokens. This issue is fixed in versions 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1.

Affected

11 ranges

Vendor	Product	Version range	Fixed in
broadcom	rabbitmq_server	>= 3.13.0 < 3.13.15	3.13.15
broadcom	rabbitmq_server	>= 4.0.0 < 4.0.22	4.0.22
broadcom	rabbitmq_server	>= 4.1.0 < 4.1.11	4.1.11
broadcom	rabbitmq_server	>= 4.2.0 < 4.2.6	4.2.6
broadcom	rabbitmq_server	>= 4.3.0 < 4.3.1	4.3.1
rabbitmq	rabbitmq-server	—	—
rabbitmq	rabbitmq-server	—	—
rabbitmq	rabbitmq-server	—	—
rabbitmq	rabbitmq-server	—	—
rabbitmq	rabbitmq-server	—	—
rabbitmq	rabbitmq-server	—	—

CVSS provenance

nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvdv4.06.0MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/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

vendor_redhat6.0MEDIUM

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