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Full vulnerability report · 2020
CVE-2020-26259High confidence

XStream is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling

x-stream · xstream

Official source article: GitHub GHSA-JFVX-7WRX-43FH ↗. Check the applicable product and release in the original source.

6.8MediumCVSS 3.1
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Mitigation available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:High, raised one band.upgradedsince 4 Aug 2024

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 82.39% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs x-stream xstream and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

4 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcelibxstream-javaVendor fix publishedDebian records a fixed source-package version for this release.1.4.15-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcelibxstream-javaVendor fix publishedDebian records a fixed source-package version for this release.1.4.15-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcelibxstream-javaVendor fix publishedDebian records a fixed source-package version for this release.1.4.15-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcelibxstream-javaVendor fix publishedDebian records a fixed source-package version for this release.1.4.15-1Debian Security Tracker ↗Source updated 5 Oct 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2020-1497

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Mitigation available
01

What, why and how

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling. The vulnerability may allow a remote attacker to delete arbitrary know files on the host as log as the executing process has sufficient rights only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist running Java 15 or higher. No user is affected, who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.

What

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling. The vulnerability may allow a remote attacker to delete arbitrary know files on the host as log as the executing process has sufficient rights only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist running Java 15 or higher. No user is affected, who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.

Why

Untrusted input is incorporated into an operating-system command without safe parameter handling.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling. The vulnerability may allow a remote attacker to delete arbitrary know files on the host as log as the executing process has sufficient rights only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist running Java 15 or higher. No user is affected, who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.

Why

Untrusted input is incorporated into an operating-system command without safe parameter handling.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-78 ↗

CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'). The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-78Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-0180Dell Data Protection Advisor: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Dell Data Protection Advisor ausnutzen, um beliebigen Code auszuführen, einen Denial-of-Service-Zustand zu erzeugen, Sicherheitsmaßnahmen zu umgehen und nicht näher spezifizierte Angriffe zu starten.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20201223Security Bulletin 23 Dec 2020

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 23 Dec 2020, published on 23 December 2020. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-951Multiples vulnérabilités dans le noyau Linux de RedHat

d?id=CVE-2019-12415 Référence CVE CVE-2020-11987 https://www.cve.org/CVERecord?id=CVE-2020-11987 Référence CVE CVE-2020-11988 https://www.cve.org/CVERecord?id=CVE-2020-11988 Référence CVE CVE-2020-13943 https://www.cve.org/CVERecord?id=CVE-2020-13943 Référence CVE CVE-2020-13949 https://www.cve.org/CVERecord?id=CVE-2020-13949 Référence CVE CVE-2020-15522 https://www.cve.org/CVERecord?id=CVE-2020-15522 Référence CVE CVE-2020-17521 https://www.cve.org/CVERecord?id=CVE-2020-17521 Référence CVE CVE-2020-17527 https://www.cve.org/CVERecord?id=CVE-2020-17527 Référence CVE CVE-2020-26217 https://www.cve.org/CVERecord?id=CVE-2020-26217 Référence CVE CVE-2020-26259 https://www.cve.org/CVERecord?id=CVE-2020-26259 Référence CVE CVE-2020-27218 https://www.cve.org/CVERecord?id=CVE-2020-27218 Référence CVE CVE-2020-27223 https://www.cve.org/CVERecord?id=CVE-2020-27223 Référence CVE CVE-2020-27782 https://www.cve.org/CVERecord?id=CVE-2020-27782 Référence CVE CVE-2020-28491 https://www.cve.org/CVERecord?id=CVE-2020-28491 Référence CVE CVE-2020-2875 https://www.cve.org/CVERecord?id=CVE-2020-2875 Référence CVE CVE-2020-2934 https://www.cve.org/CVERecord?id=CVE-2020-2934 Référence CVE CVE-2020-35510 https://www.cve.org/CVERecord?id=CVE-2020-35510 Référence CVE CVE-2020-9488 https://www.cve.org/CVERecord?id=CVE-2

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-943Multiples vulnérabilités dans les produits IBM

d?id=CVE-2020-14062 Référence CVE CVE-2020-14195 https://www.cve.org/CVERecord?id=CVE-2020-14195 Référence CVE CVE-2020-14314 https://www.cve.org/CVERecord?id=CVE-2020-14314 Référence CVE CVE-2020-14385 https://www.cve.org/CVERecord?id=CVE-2020-14385 Référence CVE CVE-2020-24616 https://www.cve.org/CVERecord?id=CVE-2020-24616 Référence CVE CVE-2020-24750 https://www.cve.org/CVERecord?id=CVE-2020-24750 Référence CVE CVE-2020-25649 https://www.cve.org/CVERecord?id=CVE-2020-25649 Référence CVE CVE-2020-26217 https://www.cve.org/CVERecord?id=CVE-2020-26217 Référence CVE CVE-2020-26258 https://www.cve.org/CVERecord?id=CVE-2020-26258 Référence CVE CVE-2020-26259 https://www.cve.org/CVERecord?id=CVE-2020-26259 Référence CVE CVE-2020-28469 https://www.cve.org/CVERecord?id=CVE-2020-28469 Référence CVE CVE-2020-35728 https://www.cve.org/CVERecord?id=CVE-2020-35728 Référence CVE CVE-2020-36179 https://www.cve.org/CVERecord?id=CVE-2020-36179 Référence CVE CVE-2020-36180 https://www.cve.org/CVERecord?id=CVE-2020-36180 Référence CVE CVE-2020-36181 https://www.cve.org/CVERecord?id=CVE-2020-36181 Référence CVE CVE-2020-36182 https://www.cve.org/CVERecord?id=CVE-2020-36182 Référence CVE CVE-2020-36183 https://www.cve.org/CVERecord?id=CVE-2020-36183 Référence CVE CVE-2020-36184 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-490Multiples vulnérabilités dans IBM Spectrum Protect

érer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation). Documentation Bulletin de sécurité IBM 6466435 du 28 juin 2021 https://www.ibm.com/support/pages/node/6466435 Bulletin de sécurité IBM 6466599 du 28 juin 2021 https://www.ibm.com/support/pages/node/6466599 Bulletin de sécurité IBM 6467281 du 28 juin 2021 https://www.ibm.com/support/pages/node/6467281 Référence CVE CVE-2020-14147 https://www.cve.org/CVERecord?id=CVE-2020-14147 Référence CVE CVE-2020-26217 https://www.cve.org/CVERecord?id=CVE-2020-26217 Référence CVE CVE-2020-26258 https://www.cve.org/CVERecord?id=CVE-2020-26258 Référence CVE CVE-2020-26259 https://www.cve.org/CVERecord?id=CVE-2020-26259 Référence CVE CVE-2020-28476 https://www.cve.org/CVERecord?id=CVE-2020-28476 Référence CVE CVE-2020-7929 https://www.cve.org/CVERecord?id=CVE-2020-7929 Référence CVE CVE-2021-21284 https://www.cve.org/CVERecord?id=CVE-2021-21284 Référence CVE CVE-2021-21285 https://www.cve.org/CVERecord?id=CVE-2021-21285 Référence CVE CVE-2021-21341 https://www.cve.org/CVERecord?id=CVE-2021-21341 Référence CVE CVE-2021-21342 https://www.cve.org/CVERecord?id=CVE-2021-21342 Référence CVE CVE-2021-21343 https://www.cve.org/CVERecord?id=CVE-2021-21343 Référence CVE CVE-2021-21344 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-407Multiples vulnérabilités dans le noyau Linux de Red Hat

rer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation). Documentation Bulletin de sécurité Red Hat RHSA-2021:2106 du 25 mai 2021 https://access.redhat.com/errata/RHSA-2021:2106 Bulletin de sécurité Red Hat RHSA-2021:2139 du 26 mai 2021 https://access.redhat.com/errata/RHSA-2021:2139 Référence CVE CVE-2020-0466 https://www.cve.org/CVERecord?id=CVE-2020-0466 Référence CVE CVE-2020-10771 https://www.cve.org/CVERecord?id=CVE-2020-10771 Référence CVE CVE-2020-12362 https://www.cve.org/CVERecord?id=CVE-2020-12362 Référence CVE CVE-2020-26258 https://www.cve.org/CVERecord?id=CVE-2020-26258 Référence CVE CVE-2020-26259 https://www.cve.org/CVERecord?id=CVE-2020-26259 Référence CVE CVE-2020-28374 https://www.cve.org/CVERecord?id=CVE-2020-28374 Référence CVE CVE-2021-21290 https://www.cve.org/CVERecord?id=CVE-2021-21290 Référence CVE CVE-2021-21295 https://www.cve.org/CVERecord?id=CVE-2021-21295 Référence CVE CVE-2021-21341 https://www.cve.org/CVERecord?id=CVE-2021-21341 Référence CVE CVE-2021-21342 https://www.cve.org/CVERecord?id=CVE-2021-21342 Référence CVE CVE-2021-21343 https://www.cve.org/CVERecord?id=CVE-2021-21343 Référence CVE CVE-2021-21344 https://www.cve.org/CVERecord?id=CVE-2021-21344 Référence CVE CVE-2021-21345 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2020-014484Xstream における OS コマンドインジェクションの脆弱性

Xstream には、OS コマンドインジェクションの脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Mitigation available
Affected
xstream: < 1.4.15
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Apply the mitigation in the linked authoritative guidance while planning the vendor's permanent fix.
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 16 Dec 2020 · Last source change 4 Aug 2024, 15:56 UTC · CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2020-1497
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2020-26259 · cve.blacktree.nl