Libxml2: libxml2: denial of service via crafted xsd-validated document
Red Hat · Red Hat Hardened Images
6.5MediumCVSS 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.
Patch available
Direct vendor intelligence
Authoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
1 current
CVE-2026-6732 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitylibxml2: libxml2: Denial of Service via crafted XSD-validated document
1 known affected
The vendor explicitly identifies these products as affected by this CVE.
libxml2 as a component of Red Hat JBoss Core Services
Summary
A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.
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-2026-25346
No EUVD known-exploited evidence
A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.
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
6.5 · CVSS 3.1
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.
Patch available
01
What, why and how
A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.
What
A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.
Why
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
How
An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
What
A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.
Why
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
How
An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
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
an adjacent network → Access of Resource Using Incompatible Type ('Type Confusion') → disrupt the affected service
Attack surface
Adjacent
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-843: Access of Resource Using Incompatible Type ('Type Confusion'). The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
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.
UnauthenticatedDenial of serviceCWE-843Public exploit reference
A
Official authority intelligence
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2026-25346Official EUVD mapping
A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.
Official EUVD recordBSI · German · WID-SEC-W-2026-3167Hitachi Energy RTU500: Mehrere Schwachstellen
Ein Angreifer kann mehrere Schwachstellen in Hitachi Energy RTU500 ausnutzen um Denial-of-Service-Zustände durch Anwendungsabstürze zu verursachen, Cookies oder Authentifizierungsinformationen an unbeabsichtigte Gegenstellen offenzulegen oder vorgesehene Authentifizierungskonfigurationen zu umgehen.
Official advisoryBSI · German · WID-SEC-W-2026-3038Meinberg LANTIME: Mehrere Schwachstellen
Ein Angreifer kann mehrere Schwachstellen in Meinberg LANTIME ausnutzen, um beliebigen Code auszuführen, Berechtigungen zu erweitern, Sicherheitsmaßnahmen zu umgehen, sensible Informationen offenzulegen, Daten zu manipulieren oder Denial-of-Service-Zustände herbeizuführen.
Official advisoryBSI · German · WID-SEC-W-2026-1257libxml2: Schwachstelle ermöglicht Denial of Service
Ein Angreifer aus einem angrenzenden Netzwerk kann eine Schwachstelle in libxml2 ausnutzen, um einen Denial of Service Angriff durchzuführen.
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.
Patch available
Affected
libxml2 as a component of Red Hat JBoss Core Services
Fixed
libxml2-main@aarch64 as a component of Red Hat Hardened Images; libxml2-main@src as a component of Red Hat Hardened Images; libxml2-main@x86_64 as a component of Red Hat Hardened Images
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 23 Apr 2026 · Last source change 31 Aug 2026, 11:15 UTC · CWE-843 · Access of Resource Using Incompatible Type ('Type Confusion')
CVE recordCVE.org · 5.2
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-2026-25346
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Affected versionsThe structured affected or fixed version information changed.
Before
libxml2 as a component of Red Hat Enterprise Linux 10; libxml2-devel as a component of Red Hat Enterprise Linux 10; libxml2-static as a component of Red Hat Enterprise Linux 10; libxml2.src as a component of Red Hat Enterprise Linux 10; python3-libxml2 as a component of Red Hat Enterprise Linux 10; libxml2 as a component of Red Hat Enterprise Linux 6; libxml2-devel as a component of Red Hat Enterprise Linux 6; libxml2-python as a component of Red Hat Enterprise Linux 6; libxml2-static as a component of Red Hat Enterprise Linux 6; libxml2.src as a component of Red Hat Enterprise Linux 6; libxml2 as a component of Red Hat Enterprise Linux 7; libxml2-devel as a component of Red Hat Enterprise Linux 7; libxml2-python as a component of Red Hat Enterprise Linux 7; libxml2-static as a component of Red Hat Enterprise Linux 7; libxml2.src as a component of Red Hat Enterprise Linux 7; libxml2 as a component of Red Hat Enterprise Linux 8; libxml2-devel as a component of Red Hat Enterprise Linux 8; libxml2.src as a component of Red Hat Enterprise Linux 8; python3-libxml2 as a component of Red Hat Enterprise Linux 8; libxml2 as a component of Red Hat Enterprise Linux 9; libxml2-devel as a component of Red Hat Enterprise Linux 9; libxml2.src as a component of Red Hat Enterprise Linux 9; python3-libxml2 as a component of Red Hat Enterprise Linux 9; libxml2 as a component of Red Hat JBoss Core Services; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · Fixed: libxml2-main@aarch64 as a component of Red Hat Hardened Images; libxml2-main@src as a component of Red Hat Hardened Images; libxml2-main@x86_64 as a component of Red Hat Hardened Images
After
libxml2 as a component of Red Hat JBoss Core Services · Fixed: libxml2-main@aarch64 as a component of Red Hat Hardened Images; libxml2-main@src as a component of Red Hat Hardened Images; libxml2-main@x86_64 as a component of Red Hat Hardened Images
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.
CVE-2026-6732: Libxml2: libxml2: denial of service via crafted xsd-validated document | BlackTree
