Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 8.96% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2025
CVE-2025-27533High confidence
Apache ActiveMQ: Unchecked buffer length can cause excessive memory allocation
Apache Software Foundation · Apache ActiveMQ
6.9MediumCVSS 4.0
Scheduled
Fix not verifiedMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Apache Software Foundation Apache ActiveMQ and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
4 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | activemq | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.17.6+dfsg-2 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian bookwormbookworm · source | activemq | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian sidsid · source | activemq | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.17.6+dfsg-2 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | activemq | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
Open-source package ranges16 source-attributed ranges
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| Mavenorg.apache.activemq:activemq-client | ECOSYSTEM: introduced 0; fixed 5.16.8 | 5.16.8 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavenorg.apache.activemq:activemq-client | ECOSYSTEM: introduced 5.17.0; fixed 5.17.7 | 5.17.7 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavenorg.apache.activemq:activemq-client | ECOSYSTEM: introduced 5.18.0; fixed 5.18.7 | 5.18.7 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavenorg.apache.activemq:activemq-client | ECOSYSTEM: introduced 6.0.0; fixed 6.1.6 | 6.1.6 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavenorg.apache.activemq:activemq-openwire-legacy | ECOSYSTEM: introduced 0; fixed 5.16.8 | 5.16.8 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavenorg.apache.activemq:activemq-openwire-legacy | ECOSYSTEM: introduced 5.17.0; fixed 5.17.7 | 5.17.7 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavenorg.apache.activemq:activemq-openwire-legacy | ECOSYSTEM: introduced 5.18.0; fixed 5.18.7 | 5.18.7 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavenorg.apache.activemq:activemq-openwire-legacy | ECOSYSTEM: introduced 6.0.0; fixed 6.1.6 | 6.1.6 | OSV record ↗aggregator derived · 10 Sep 2026 |
| mavenorg.apache.activemq:activemq-client | < 5.16.8 | 5.16.8 | GitHub advisory ↗github reviewed aggregator · 3 Nov 2025 |
| mavenorg.apache.activemq:activemq-client | >= 5.17.0, < 5.17.7 | 5.17.7 | GitHub advisory ↗github reviewed aggregator · 3 Nov 2025 |
| mavenorg.apache.activemq:activemq-client | >= 5.18.0, < 5.18.7 | 5.18.7 | GitHub advisory ↗github reviewed aggregator · 3 Nov 2025 |
| mavenorg.apache.activemq:activemq-client | >= 6.0.0, < 6.1.6 | 6.1.6 | GitHub advisory ↗github reviewed aggregator · 3 Nov 2025 |
| mavenorg.apache.activemq:activemq-openwire-legacy | < 5.16.8 | 5.16.8 | GitHub advisory ↗github reviewed aggregator · 3 Nov 2025 |
| mavenorg.apache.activemq:activemq-openwire-legacy | >= 5.17.0, < 5.17.7 | 5.17.7 | GitHub advisory ↗github reviewed aggregator · 3 Nov 2025 |
| mavenorg.apache.activemq:activemq-openwire-legacy | >= 5.18.0, < 5.18.7 | 5.18.7 | GitHub advisory ↗github reviewed aggregator · 3 Nov 2025 |
| mavenorg.apache.activemq:activemq-openwire-legacy | >= 6.0.0, < 6.1.6 | 6.1.6 | GitHub advisory ↗github reviewed aggregator · 3 Nov 2025 |
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Fix not verified01
What, why and how
Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ. During unmarshalling of OpenWire commands the size value of buffers was not properly validated which could lead to excessive memory allocation and be exploited to cause a denial of service (DoS) by depleting process memory, thereby affecting applications and services that rely on the availability of the ActiveMQ broker when not using mutual TLS connections. This issue affects Apache ActiveMQ: from 6.0.0 before 6.1.6, from 5.18.0 before 5.18.7, from 5.17.0 before 5.17.7, before 5.16.8. ActiveMQ 5.19.0 is not affected. Users are recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8 or which fixes the issue. Existing users may implement mutual TLS to mitigate the risk on affected brokers.
What
Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ. During unmarshalling of OpenWire commands the size value of buffers was not properly validated which could lead to excessive memory allocation and be exploited to cause a denial of service (DoS) by depleting process memory, thereby affecting applications and services that rely on the availability of the ActiveMQ broker when not using mutual TLS connections. This issue affects Apache ActiveMQ: from 6.0.0 before 6.1.6, from 5.18.0 before 5.18.7, from 5.17.0 before 5.17.7, before 5.16.8. ActiveMQ 5.19.0 is not affected. Users are recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8 or which fixes the issue. Existing users may implement mutual TLS to mitigate the risk on affected brokers.
Why
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
How
An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may disrupt the affected service.
What
Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ. During unmarshalling of OpenWire commands the size value of buffers was not properly validated which could lead to excessive memory allocation and be exploited to cause a denial of service (DoS) by depleting process memory, thereby affecting applications and services that rely on the availability of the ActiveMQ broker when not using mutual TLS connections. This issue affects Apache ActiveMQ: from 6.0.0 before 6.1.6, from 5.18.0 before 5.18.7, from 5.17.0 before 5.17.7, before 5.16.8. ActiveMQ 5.19.0 is not affected. Users are recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8 or which fixes the issue. Existing users may implement mutual TLS to mitigate the risk on affected brokers.
Why
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
How
An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may disrupt the affected service.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Memory Allocation with Excessive Size Value → disrupt the affected service
- Attack surface
- Network
- Privileges required
- High: elevated access is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-789 ↗
CWE-789: Memory Allocation with Excessive Size Value. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/AU:Y/R:A/V:D/RE:M/U:RedCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SAHighSubsequent-system availability: A successful attack can cause a major loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix not verified
- Affected
- Apache ActiveMQ: 6.0.0 < 6.1.6, 5.18.0 < 5.18.7, 5.17.0 < 5.17.7, 5.16.0 < 5.16.8
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 7 May 2025 · Last source change 3 Nov 2025, 19:45 UTC · CWE-789 · Memory Allocation with Excessive Size Value
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2025-13714
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD modified after enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.