RabbitMQ: Trust-store whitelist by Issuer+Serial only (CVE-2026-67231) | HOL Guard CVE

Critical · CVSS 9.1CVE-2026-67231

RabbitMQ: Trust-store whitelist by Issuer+Serial only

Answer in brief

CVE-2026-67231 records a Critical severity (CVSS 9.1) vulnerability in RabbitMQ: Trust-store whitelist by Issuer+Serial only. The current sources do not mark it as known exploited. The current feed maps rabbitmq/rabbitmq-server (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 23, 2026Updated Sep 23, 2026Source checked Sep 24, 2026First seen by HOL Sep 23, 2026Material review Sep 23, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 9.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps rabbitmq/rabbitmq-server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
rabbitmq/rabbitmq-servergeneric	>=3.13.0 <3.13.15 \|\| >=4.0.0 <4.0.20 \|\| >=4.1.0 <4.1.11 \|\| >=4.2.0 <4.2.6	3.13.15, 4.0.20, 4.1.11, 4.2.6

Recommended response

Check inventory. Check lockfiles and deployed manifests for rabbitmq/rabbitmq-server.
Review the reported fix. Update rabbitmq/rabbitmq-server to 3.13.15 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 23, 2026

Sources and claim methodology

Upstream source description

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, The trust-store plugin installs a verify_fun that overrides {bad_cert, unknown_ca} / {bad_cert, selfsigned_peer} when the presented cert "matches" a whitelisted one. The match key is extract_issuer_id/1 → public_key:pkix_issuer_id/2 → {IssuerName, SerialNumber} , both fields are taken verbatim from the presented certificate body and contain no public-key, SKI, fingerprint or signature material. is_whitelisted/1 is a pure ets:member lookup; the stored full DER is used only for list/0 display and is never compared against the presented cert. cacerts is [], so the whitelisted cert is never used as a trust anchor for path validation either. TLS client-authentication bypass: an attacker who knows the issuer DN + serial of any whitelisted certificate can connect with a forged self-signed cert. Preconditions include rabbitmq_trust_store plugin enabled and used as the TLS verify_fun Attacker knows or can guess the {Issuer, Serial} of at least one whitelisted cert (non-secret; exposed via CLI/logs/any cert copy). This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.

Quoted source text, attributed separately from HOL analysis.