CVE-2026-27446: Apache Artemis and Apache ActiveMQ Artemis are Missing Authentication for Critical Functions

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 1.2%, percentile 67: FIRST’s model estimates a 1.2% chance of exploitation activity in the next 30 days, higher than 67% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes org.apache.activemq:artemis-server (Maven) >= 2.11.0, <= 2.44.0, no fixed version listed; org.apache.artemis:artemis-server (Maven) >= 2.50.0, < 2.52.0, fixed in 2.52.0. Check your lockfile, including transitive dependencies.

What it is

Missing Authentication for Critical Function (CWE-306) vulnerability in Apache Artemis, Apache ActiveMQ Artemis. An unauthenticated remote attacker can use the Core protocol to force a target broker to establish an outbound Core federation connection to an attacker-controlled rogue broker. This could potentially result in message injection into any queue and/or message exfiltration from any queue via the rogue broker. This impacts environments that allow both: - incoming Core protocol connections from untrusted sources to the broker - outgoing Core protocol connections from the broker to untrusted targets This issue affects: - Apache Artemis from 2.50.0 through 2.51.0 - Apache ActiveMQ Artemis from 2.11.0 through 2.44.0. Users are recommended to upgrade to Apache Artemis version 2.52.0, which fixes the issue. The issue can be mitigated by one of the following: - Remove Core protocol support from any acceptor receiving connections from untrusted sources. Incoming Core protocol connections are supported by default via the "artemis" acceptor listening on port 61616. See the "protocols" URL parameter configured for the acceptor. An acceptor URL without this parameter supports all protocols by default, including Core. - Use two-way SSL (i.e. certificate-based authentication) in order to force every client to present the proper SSL certificate when establishing a connection before any message protocol handshake is attempted. This will prevent unauthenticated exploitation of this vulnerability. - Implement and deploy a Core interceptor to deny all Core downstream federation connect packets. Such packets have a type of (int) -16 or (byte) 0xfffffff0. Documentation for interceptors is available at https://artemis.apache.org/components/artemis/documentation/latest/intercepting-operations.html .

From the GitHub advisory

Missing Authentication for Critical Function (CWE-306) vulnerability in Apache Artemis, Apache ActiveMQ Artemis. An unauthenticated remote attacker can use the Core protocol to force a target broker to establish an outbound Core federation connection to an attacker-controlled rogue broker. This could potentially result in message injection into any queue and/or message exfiltration from any queue via the rogue broker. This impacts environments that allow both:

- Incoming Core protocol connections from untrusted sources to the broker

- Outgoing Core protocol connections from the broker to untrusted targets

This issue affects:

- Apache Artemis from 2.50.0 through 2.51.0

Weakness type: CWE-306.

Product: org.apache.activemq:artemis-server (Maven) · Assigned by: apache · Published: 2026-03-04

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 1.18% probability of exploitation activity in the next 30 days; percentile 67.

Timeline

• 2026-03-04 — CVE record published by apache
• 2026-03-04 — GitHub-reviewed advisory GHSA-fw88-pf9m-p947 published (critical)
• 2026-09-18 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. lists.apache.org lists.apache.org
2. access.redhat.com access.redhat.com
3. access.redhat.com access.redhat.com
4. access.redhat.com access.redhat.com
5. access.redhat.com access.redhat.com
6. access.redhat.com access.redhat.com
7. access.redhat.com access.redhat.com
8. access.redhat.com access.redhat.com
9. access.redhat.com access.redhat.com
10. access.redhat.com access.redhat.com

Vulnerability records

1. GitHub Advisory GHSA-fw88-pf9m-p947 github.com
2. CVE.org record CVE-2026-27446 cve.org
3. NVD entry CVE-2026-27446 nvd.nist.gov

Other references from the CVE record and advisory

1. openwall.com openwall.com
2. openwall.com openwall.com
3. cert-portal.siemens.com cert-portal.siemens.com
4. access.redhat.com access.redhat.com
5. RHBZ#2444320 bugzilla.redhat.com
6. security.access.redhat.com security.access.redhat.com

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