CVE-2026-66072

RabbitMQ: Atom table exhaustion via stream `chunk_selector`

MEDIUM
6.5
CVSS Score
Published: September 23, 2026 at 08:13 PM UTC
Updated: October 19, 2026 at 08:37 PM UTC
2 products affected across 2 vendorsRabbitmq ServerRabbitmq Server

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.5%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.13.0 ≤ v < 3.13.154.0.0 ≤ v < 4.0.204.1.0 ≤ v < 4.1.114.2.0 ≤ v < 4.2.64.3.0 ≤ v < 4.3.1
Affected range stops below 3.13.15, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.0.20, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.1.11, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.2.6, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.3.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400

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