CVE-2026-49432: Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Stomp: STOMP negative content-length enables denial of service

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-30 · updated 2026-07-02
Weakness: CWE-20

Description

Improper Input Validation vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Stomp. A remote unauthenticated peer that can reach an exposed STOMP connector can trigger denial-of-service behavior by sending a negative content-length. For the NIO STOMP transport, an attacker can keep streaming body bytes and grow the per-connection command buffer beyond configured limits to cause OOM. For the blocking STOMP protocol, an error will instead force abnormal transport exception handling for the affected connection and closure. This issue affects 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; Apache ActiveMQ Stomp: 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.

Affected products

Apache ActiveMQ: before 5.19.8; from 6.0.0 before 6.2.7 — fixed in 5.19.8, 6.2.7

How to fix

Upgrade to a fixed version: Apache ActiveMQ 5.19.8, 6.2.7. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-49432 or the next vulnerability affects your stack