Remote Code Execution in XStream

Summary

XStream before version 1.4.14 is vulnerable to Remote Code Execution.The vulnerability may allow a remote attacker to run arbitrary shell commands only by manipulating the processed input stream. Only users who rely on blocklists are affected. Anyone using XStream's Security Framework allowlist is not affected. The linked advisory provides code workarounds for users who cannot upgrade. The issue is fixed in version 1.4.14.

Timeline

1. Nov 16, 2020, 9:00 PM UTCCVE published
2. Oct 7, 2026, 6:50 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: total

3. Oct 7, 2026, 6:51 PM UTCRecord last updated
4. Oct 22, 2026EPSS reached 10%

   FIRST estimates at least a 10% chance of exploitation in the next 30 days

Affected versions

• x-stream xstream

  fixed in 1.4.14

• activemqBitnami

  fixed in 5.15.14; From 5.16.0 · through 5.16.0

• com.thoughtworks.xstream:xstreamMaven

  fixed in 1.4.14-java7

References 15