CVE-2026-50734

HIGH 7.5

Published 2026-06-30 · Last modified 2026-06-30

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ Client, Apache ActiveMQ, Apache ActiveMQ All. An unauthenticated network attacker can cause a broker DoS by sending a crafted WireFormatInfo frame with a malicious large size value. The value is not validate and causes the broker to attempt allocation during pre-auth negotiation which can trigger OOM and crash the broker. This issue affects Apache ActiveMQ Client: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ All: before 5.19.8, from 6.0.0 before 6.2.7. Users are recommended to upgrade to version 6.2.7 or 5.19.8, which fixes the issue.

ELEVATED IMPACT

Severe if exploited (CVSS 7.5), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.8%chance of exploitation in 30 days · 52nd percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

7.5CVSS 3.1 · HIGH

ConfidentialityNone
IntegrityNone
AvailabilityHigh

What an attacker needs

✓Access: Reachable over the network — no local access needed
✓Privileges: No account or privileges required
✓User interaction: No user interaction needed
✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

github-search Search GitHub for public PoC repos

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-50734/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-50734/poc.json

Affected

Vendors Apache Software Foundation Apache

Products Apache Activemq Client Apache Activemq Apache Activemq All Activemq

Weakness (CWE)

CWE-789: Memory Allocation with Excessive Size Value

CVSS vector

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

Known Affected Software Configurations

Vendor	Product	Version range
Apache	Activemq	< 5.19.8
Apache	Activemq	≥ 6.0.0 and < 6.2.7

All CVSS metrics

HIGH 7.5 v3.1 · ADP Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
HIGH 7.5 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Advisories

https://lists.apache.org/thread/nxso951fnvf72qf9m475mpz4yf931xk0 vendor-advisoryVendor AdvisoryMailing List
http://www.openwall.com/lists/oss-security/2026/06/29/10 Third Party Advisory

Sources: NVD · CVE.org · EPSS