Answer in brief
CVE-2020-26217 records a High severity (CVSS 8.0) vulnerability in Remote Code Execution in XStream. The current sources do not mark it as known exploited. The current feed maps x-stream/xstream (generic), com.thoughtworks.xstream:xstream (maven). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps x-stream/xstream (generic), com.thoughtworks.xstream:xstream (maven). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| x-stream/xstreamgeneric | <1.4.14 | 1.4.14 |
| com.thoughtworks.xstream:xstreammaven | >=0 <1.4.14-java7 | 1.4.14-java7 |
Published upstream
Nov 16, 2020
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 8, 2026
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.
Quoted source text, attributed separately from HOL analysis.