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VulnerabilityCVE-2026-42253Published 2026-06-01

CVE-2026-42253 — Apache ActiveMQ

medium

As of 2026-06-03, CVE-2026-42253 is a MEDIUM-severity vulnerability in Apache ActiveMQ, CVSS v3.1 6.1, EPSS 0.6% (50.9th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-42253, most recently “Apache ActiveMQ MessageServlet HTTP Response Header Injection (CVE-2026-42253) and Jolokia Default-Permission Privilege Issue (CVE-2026-49157)”.

CVSS v3.1
6.1/10Medium
EPSS
0.6%Higher than 50.9% of scored CVEs
CISA KEV
NoNot in the KEV catalog
Tracked threats
1Campaigns referencing it
Priority
5.1/10Threadlinqs triage score
Published
Updated 2026-06-03
CVSS v3.1 6.1 (MEDIUM) · EPSS 0.6% (higher than 50.9% of all scored CVEs) · Priority 5.1/10 · Published 2026-06-01

Last updated:

What is CVE-2026-42253?

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache ActiveMQ, Apache ActiveMQ Web. The MessageServlet in the ActiveMQ web console API copies every JMS message property into an HTTP response header without any validation. This can allow overwriting and injecting security headers by setting them on JMS messages that are returned by the servlet. This issue affects Apache ActiveMQ: before 5.19.7, from 6.0.0 before 6.2.6; Apache ActiveMQ Web: before 5.19.7, from 6.0.0 before 6.2.6. Users are recommended to upgrade to version 5.19.7 or 6.2.6, which fixes the issue. The MessageServlet has now been deprecated and disabled by default.

The record classifies CVE-2026-42253 under weakness class CWE-79. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 137 days ago.

Severity and exploitation probability

CVSS v3.1 base score
6.1 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS (FIRST)
0.6% probability of exploitation in the next 30 days, higher than 50.9% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
5.1/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-06-01, last modified 2026-06-03

Is CVE-2026-42253 being exploited?

It currently carries a trending score of 18 in the Threadlinqs vulnerability feed.

Affected products and versions

Affected software packages:

  • maven:org.apache.activemq:apache-activemq — patched in 5.19.7
  • maven:org.apache.activemq:apache-activemq — patched in 6.2.6
  • maven:org.apache.activemq:activemq-web — patched in 5.19.7
  • maven:org.apache.activemq:activemq-web — patched in 6.2.6

How to fix CVE-2026-42253

Fixed versions are recorded for 4 packages: maven:org.apache.activemq:apache-activemq 5.19.7, maven:org.apache.activemq:apache-activemq 6.2.6, maven:org.apache.activemq:activemq-web 5.19.7, maven:org.apache.activemq:activemq-web 6.2.6. No vendor patch reference has been recorded for CVE-2026-42253 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-42253

1 tracked threat in the Threadlinqs corpus references CVE-2026-42253, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on .

Vendor advisory and patch