Vulnerability · Published Sep 23, 2026 · Assigned by GitHub_M

CVE-2026-66072RabbitMQ: Atom table exhaustion via stream `chunk_selector`

Medium 6.0

In plain English

A medium-severity uncontrolled resource consumption in rabbitmq-server from rabbitmq. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.0Medium

Exploit odds (30 days)0.5%top 58.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1, get_chunk_selector/1 calls binary_to_atom on the raw client-supplied <<"chunk_selector">> property from post-auth subscribe and resolve_offset_spec frames, with no whitelist and no existing guard. An authenticated stream client with read access to any stream can crash the broker node. Preconditions include rabbitmq_stream plugin enabled Authenticated stream-protocol user with read access to at least one stream. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	rabbitmq-server	no fix listed	DEBIAN-CVE-2026-66072
Debian:13	rabbitmq-server	no fix listed	DEBIAN-CVE-2026-66072
Debian:14	rabbitmq-server	4.3.2-1	DEBIAN-CVE-2026-66072
Ubuntu:22.04:LTS	rabbitmq-server	no fix listed	UBUNTU-CVE-2026-66072
Ubuntu:24.04:LTS	rabbitmq-server	no fix listed	UBUNTU-CVE-2026-66072
Ubuntu:26.04:LTS	rabbitmq-server	no fix listed	UBUNTU-CVE-2026-66072

Affected products (as reported)

Vendor	Product	Versions
rabbitmq	rabbitmq-server	>= 3.13.0, < 3.13.15>= 4.0.0, < 4.0.20>= 4.1.0, < 4.1.11>= 4.2.0, < 4.2.6>= 4.3.0, < 4.3.1

Weakness: CWE-400 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-48hm-chgv-398r x_refsource_CONFIRM
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6 x_refsource_MISC
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1 x_refsource_MISC