Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
OpenDJ (opendj-server-legacy, Maven) versions before 5.1.1 are affected. An unauthenticated remote attacker who can reach the JMX RMI connector handler, which is disabled by default but often enabled for monitoring, can trigger Java deserialization of attacker-supplied data on the server. This can lead to remote code execution, depending on the server's classpath and Java version. Upgrade to version 5.1.1. Disabling the JMX Connection Handler if it is not needed reduces exposure.
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 |
|---|---|---|---|---|
| 9.2 | Critical | 4.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.011, the 66th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:20 UTC First seen by agentprime
- 31 Oct 2026, 14:20 UTC Confirmed by OSV