Vulnerability in activemq (CVE-2026-39304)
Summary
Vulnerability in activemq (CVE-2026-39304). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.19.4, 6.2.4 or later.
Original description
The description as published by the source.
Denial of Service via Out of Memory vulnerability in Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ.
ActiveMQ NIO SSL transports do not correctly handle TLSv1.3 handshake KeyUpdates triggered by clients. This makes it possible for a client to rapidly trigger updates which causes the broker to exhaust all its memory in the SSL engine leading to DoS.
Note: TLS versions before TLSv1.3 (such as TLSv1.2) are broken but are not vulnerable to OOM. Previous TLS versions require a full handshake renegotiation which causes a connection to hang but not OOM. This is fixed as well.
This issue affects Apache ActiveMQ Client: before 5.19.4, from 6.0.0 before 6.2.4; Apache ActiveMQ Broker: before 5.19.4, from 6.0.0 before 6.2.4; Apache ActiveMQ: before 5.19.4, from 6.0.0 before 6.2.4.
Users are recommended to upgrade to version 6.2.4 or 5.19.5, which fixes the issue.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-39304 has been found in activemq.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade activemq to 5.19.4, 6.2.4 or later.
If unsure, ask your IT team or search "activemq CVE-2026-39304" on the vendor's site.
CVE-2026-39304 (activemq) — CWE-400 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 5.19.4, 6.2.4 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in activemq.
Check the vendor advisory for the affected versions of activemq.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 5.19.4, 6.2.4.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'activemq' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'activemq' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
activemqを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade activemq to 5.19.4, 6.2.4ステージング環境で 5.19.4, 6.2.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-39304 activemq
- Ubuntu UBUNTU-CVE-2026-39304 activemq
References
- advisory activemq.apache.org
- advisory openwall.com
- web access.redhat.com
- web bugzilla.redhat.com
- web security.access.redhat.com
- web nvd.nist.gov