Reference page — cumulative record through Thursday, October 8, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2020-26217

CVE-2020-26217HIGH

x-stream xstream — Remote Code Execution in XStream

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   L   N  U  H  H  H    8.8   .8500   99.7     —

AFFECTED
  Product  Versions    Fixed
  xstream  < 1.4.14 –  —

TIMELINE
  Oct 1   Reserved by GitHub_M
  Nov 16  Published (CNA: GitHub_M)
  Oct 7   EXPLOIT PUBLISHED — CVE-2020-26217 (x-stream xstream). Public exploit reference added.
  Oct 7   RESCORED — CVE-2020-26217 (x-stream xstream). CVSS 8 → 8.8 (NVD).

CWE-78 · CNA: GitHub_M · CVSS v3.1 · 15 references · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
October 1, 2020	Reserved	Reserved by GitHub_M
November 16, 2020	Published	Published (CNA: GitHub_M)
October 7, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2020-26217 (x-stream xstream). Public exploit reference added.
October 7, 2026	RESCORED	RESCORED — CVE-2020-26217 (x-stream xstream). CVSS 8 → 8.8 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
x-stream	xstream	—	< 1.4.14	—

Weaknesses

CWE-78

References (15)

https://github.com/x-stream/xstream/commit/0fec095d534126931c99fd38e9c6d41f5c685c1a [Patch, Third Party Advisory]
https://github.com/x-stream/xstream/security/advisories/GHSA-mw36-7c6c-q4q2 [Mitigation, Third Party Advisory]
https://lists.apache.org/thread.html/r2de526726e7f4db4a7cb91b7355070779f51a84fd985c6529c2f4e9e%40%3Cissues.activemq.apache.org%3E [Issue Tracking, Mailing List]
https://lists.apache.org/thread.html/r7c9fc255edc0b9cd9567093d131f6d33fde4c662aaf912460ef630e9%40%3Ccommits.camel.apache.org%3E [Issue Tracking, Mailing List]
https://lists.apache.org/thread.html/r826a006fda71cc96fc87b6eca4b5d195f19a292ad36cea501682c38c%40%3Cissues.activemq.apache.org%3E [Issue Tracking, Mailing List]
https://lists.apache.org/thread.html/redde3609b89b2a4ff18b536a06ef9a77deb93d47fda8ed28086fa8c3%40%3Cissues.activemq.apache.org%3E [Issue Tracking, Mailing List]
https://lists.debian.org/debian-lts-announce/2020/12/msg00001.html [Mailing List, Third Party Advisory]
https://security.netapp.com/advisory/ntap-20210409-0004/ [Third Party Advisory]
https://www.debian.org/security/2020/dsa-4811 [Third Party Advisory]
https://www.oracle.com//security-alerts/cpujul2021.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpuApr2021.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpuapr2022.html [Not Applicable, Third Party Advisory]
https://www.oracle.com/security-alerts/cpujan2022.html [Not Applicable, Third Party Advisory]
https://www.oracle.com/security-alerts/cpuoct2021.html [Patch, Third Party Advisory]
https://x-stream.github.io/CVE-2020-26217.html [Exploit, Mitigation, Vendor Advisory]

Authoritative record: CVE-2020-26217 at cve.org

Vendors: x-stream

Weaknesses: CWE-78

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-26217 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Thursday, October 8, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.