Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Apache ActiveMQ Client, Broker and ActiveMQ before 5.19.4 and from 6.0.0 before 6.2.4 are affected. A client connecting over the NIO SSL transport can repeatedly trigger TLSv1.3 KeyUpdate handshakes, causing the broker to exhaust its memory in the SSL engine and denial of service. Upgrade to 6.2.4 or 5.19.4 or later; the source recommends 5.19.5.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.5 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub Advisory Database |
- CISA KEV Not listed.
- EPSS 0.0091, the 60th percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:17 UTC First seen by agentprime
- 31 Oct 2026, 14:17 UTC Confirmed by OSV