Apache Artemis vulnerability

An unauthenticated remote attacker can craft a CORE protocol SESSION_REATTACH packet to steal an existing session and assume ongoing execution of the previously authenticated session. This issue affects Apache Artemis: from 2.50.0 through 2.56.0; Apache ActiveMQ Artemis: from 1.0.0 through 2.44.0. Users are recommended to upgrade to version 2.57.0, which fixes the issue.

Published 10 Sep 2026Updated 9 Oct 202677 sources
CVSS 9.8 ✓ VERIFIED REFERENCE

What happened

An unauthenticated remote attacker can craft a CORE protocol SESSION_REATTACH packet to steal an existing session and assume ongoing execution of the previously authenticated session. This issue affects Apache Artemis: from 2.50.0 through 2.56.0; Apache ActiveMQ Artemis: from 1.0.0 through 2.44.0. Users are recommended to upgrade to version 2.57.0, which fixes the issue.

Affected versions

Apache Artemis: 2.50.0 through 2.56.0 (semver); 1.0.0 through 2.44.0 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references