CVE-2026-66079

HIGHPre-NVD 8.28.2
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 8.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6, parse_array_primitive/2 for constructor 0x45 (list0) returns an element with byte-width B = 0. The enclosing array32 parser at line 148 reads a 4-byte Count from the wire and loops Count times consuming B bytes each , with B = 0, no input is consumed and the loop builds a list of Count empty elements bounded only by the 32-bit field. The SASL-mechanisms / SASL-init frame is parsed by amqp10_framing:decode_bin/1 from rabbit_amqp_reader.erl:412 before authentication completes. The pre-auth incoming_max_frame_size (default 8192 bytes) caps the frame, not the Count field, so a 19-byte payload with Count = 0xFFFFFFFF is accepted. No max_heap_size is set on the reader process. An unauthenticated network attacker can crash any RabbitMQ node that has the AMQP 1.0 listener enabled (default port 5672) by sending a single ~19-byte frame. The reader process attempts to build a list of ~4 billion empty elements, exhausting heap memory and terminating the Erlang VM. All tenants and protocols on the node lose service. Preconditions include Network reachability to the AMQP listener (port 5672, enabled by default) No authentication required. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.

CVSS v3
8.2
EG Score
8.2(low)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity82% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

September 23, 2026

Last Modified

September 23, 2026

Advisory Details (2)

Auto-updated Sep 23, 2026
Patch available. Sources: github, github_release.
github_release Patch Available

RabbitMQ 4.2.6

Patch available: rabbitmq/rabbitmq-server v4.2.6

https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6
github Patch Available

Pre-auth AMQP 1.0 array32 zero-width element DoS · Advisory · rabbitmq/rabbitmq-server · GitHub

https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-c66h-hf5j-8jf9

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 3× in last 7d / 3× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-23 20:22 UTCEG score recompute
  2. 2026-09-23 20:03 UTCEG score recompute
  3. 2026-09-23 20:03 UTCMITRE cvelistV5first tracked

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Frequently asked(4)

What is CVE-2026-66079?
CVE-2026-66079 is a high vulnerability published on September 23, 2026. RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6, parsearrayprimitive/2 for constructor 0x45 (list0) returns an element with byte-width B = 0. The enclosing array32 parser at line 148 reads a 4-byte Count from the wire and loops Count times…
When was CVE-2026-66079 disclosed?
CVE-2026-66079 was first published in the National Vulnerability Database on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-66079?
CVE-2026-66079 has a CVSS v3 base score of 8.2 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-66079?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66079, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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