Critical

Authentication bypass in Apache Artemis Core downstream federation

IdentifiersCVE-2026-27446CWE-306· Missing Authentication for…

CVE-2026-27446 is a Missing Authentication for Critical Function vulnerability in Apache Artemis and Apache ActiveMQ Artemis affecting the broker's Core downstream federation behavior. An unauthenticated remote attacker can use the Core protocol to cause a target broker to establish an outbound Core federation connection to an attacker-controlled rogue broker. Because the vulnerable function does not properly require authentication for this critical operation, the attacker can abuse the broker-to-broker federation path to interact with queues through the rogue broker. The issue affects Apache Artemis 2.50.0 through 2.51.0 and Apache ActiveMQ Artemis 2.11.0 through 2.44.0.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can allow message injection into arbitrary queues and/or message exfiltration from arbitrary queues via the attacker-controlled rogue broker. This can compromise message integrity and confidentiality across the broker, and may enable unauthorized data access, tampering with queued workloads, and abuse of inter-broker trust relationships. The described impact is remote and unauthenticated where the affected deployment conditions are met.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, remove Core protocol support from any acceptor that receives connections from untrusted sources. Incoming Core protocol connections are enabled by default via the "artemis" acceptor on port 61616, and acceptors without an explicit "protocols" URL parameter support all protocols by default, including Core. Alternatively, enforce two-way SSL/mutual TLS so every client must present a valid certificate before any message protocol handshake occurs. Apache also states that operators can implement and deploy a Core interceptor to deny all Core downstream federation connect packets, identified as type (int) -16 or (byte) 0xfffffff0.

Remediation

Patch, then assume compromise.

Upgrade to Apache Artemis 2.52.0 or later, which fixes the issue. For affected Apache ActiveMQ Artemis deployments, move to a fixed release incorporating the Apache Artemis 2.52.0 fix as provided by the vendor or project maintainers. Review broker configurations to ensure untrusted clients cannot trigger Core downstream federation behavior without authentication.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

Apache Software FoundationActivemq Artemisapplication

Apache Software FoundationArtemisapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

12 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

12 SOURCESView more in app

cvefeed high severityNews

Mar 4, 2026

CVE-2026-27446 - Apache Artemis, Apache ActiveMQ Artemis: Auth bypass for Core downstream federation

An unauthenticated remote attacker can abuse the ActiveMQ Artemis/Core protocol federation behavior to coerce a broker into connecting to an attacker-controlled rogue broker, enabling message injection and/or message exfiltration.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware1

Malware families riding this exploit, with evidence and IOCs.

Detection signatures1

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity10