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NVD / CVE Program· CNA apache

CVE-2026-40046: Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ MQTT: Missing fix for CVE-2025-66168: MQTT control packet remaining length field is not properly validated

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.38% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Apache Software Foundation Apache ActiveMQ 6.2.4; Apache Software Foundation Apache ActiveMQ All 6.2.4; Apache Software Foundation Apache ActiveMQ MQTT 6.2.4.

Low priority for now. Upgrade to Apache Software Foundation Apache ActiveMQ 6.2.4; Apache Software Foundation Apache ActiveMQ All 6.2.4; Apache Software Foundation Apache ActiveMQ MQTT 6.2.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Integer Overflow or Wraparound vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ MQTT. The fix for "CVE-2025-66168: MQTT control packet remaining length field is not properly validated" was only applied to 5.19.2 (and future 5.19.x) releases but was missed for all 6.0.0+ versions. This issue affects Apache ActiveMQ: from 6.0.0 before 6.2.4; Apache ActiveMQ All: from 6.0.0 before 6.2.4; Apache ActiveMQ MQTT: from 6.0.0 before 6.2.4. Users are recommended to upgrade to version 6.2.4 or a 5.19.x version starting with 5.19.2 or later (currently latest is 5.19.5), which fixes the issue.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Apr 9, 2026
Updated
Oct 26, 2026
EPSS
0.3% · 32th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache ActiveMQ

    • 6.0.0 and later · before 6.2.4affected · semver

  • Apache Software Foundation Apache ActiveMQ All

    • 6.0.0 and later · before 6.2.4affected · semver

  • Apache Software Foundation Apache ActiveMQ MQTT

    • 6.0.0 and later · before 6.2.4affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Mavenorg.apache.activemq:activemq-allfrom 6.0.0 · before 6.2.46.2.4
Mavenorg.apache.activemq:activemq-mqttfrom 6.0.0 · before 6.2.46.2.4
Mavenorg.apache.activemq:apache-activemqfrom 6.0.0 · before 6.2.46.2.4

Same product

apache software foundation: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-108949Apache ActiveMQ, ActiveMQ Broker: Repeated rejected temporary destination consumer requests can lead to broker OOM
    26Monitor
  • CVE-2026-108946Apache ActiveMQ, ActiveMQ Broker: The broker does not verify user provided connection id matches connection
    0Monitor
  • CVE-2026-108500Apache ActiveMQ: LDAPAuthorizationMap allows authorization bypass via DN injection
    0Monitor

Published before and after this one in the same product

  • Later →CVE-2026-111821Nov 4, 2026 · Apache ActiveMQ, Apache ActiveMQ KahaDB: Oversized client identifier strings poison the KahaDB journal
    0Monitor
  • Later →CVE-2026-111822Nov 4, 2026 · Apache ActiveMQ, Apache ActiveMQ Runtime Config: ActiveMQ retains write access after live ACL revocation
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Apache Software Foundation Apache ActiveMQ6.2.4Vendor (CNA)
Apache Software Foundation Apache ActiveMQ All6.2.4Vendor (CNA)
Apache Software Foundation Apache ActiveMQ MQTT6.2.4Vendor (CNA)
Maven:org.apache.activemq:activemq-all6.2.4Package registry (OSV)
Maven:org.apache.activemq:activemq-mqtt6.2.4Package registry (OSV)
Maven:org.apache.activemq:apache-activemq6.2.4Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

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Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records