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Full vulnerability report · 2026
CVE-2026-84371High confidence

ApostropheCMS: Stored XSS via SVG SMIL URI-list scheme-policy bypass

apostrophecms · apostrophe

Official source article: GitHub GHSA-G8QQ-57P8-GGW5 ↗. Check the applicable product and release in the original source.

5.4MediumCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 16 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.30% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs apostrophecms apostrophe and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  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: As exposure requiresRemediation target: Within 365 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.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 16 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Open-source package ranges2 source-attributed ranges

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
npmsanitize-html>= 1.9.0, <= 2.17.62.17.7GitHub advisory ↗upstream repository advisory · 1 Sep 2026
npmsanitize-htmlSEMVER: introduced 1.9.0; fixed 2.17.72.17.7OSV record ↗aggregator derived · 10 Sep 2026
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-2026-84371 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitysanitize-html: stored XSS via SVG SMIL URI-list scheme-policy bypass
16 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • costmanagement/costmanagement-ui-rhel10 as a component of Cost Management On Premise
  • multicluster-engine/console-mce-rhel9 as a component of Multicluster Engine for Kubernetes
  • rhacm2/console-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2
  • cockpit-image-builder as a component of Red Hat Enterprise Linux 10
  • cockpit-image-builder.src as a component of Red Hat Enterprise Linux 10
  • rhoai/odh-mlflow-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
  • openshift4/ose-agent-installer-ui-rhel9 as a component of Red Hat OpenShift Container Platform 4
  • openshift4/ose-console as a component of Red Hat OpenShift Container Platform 4
  • openshift4/ose-console-rhel9 as a component of Red Hat OpenShift Container Platform 4
  • devspaces/dashboard-rhel9 as a component of Red Hat OpenShift Dev Spaces
  • quay/quay-rhel8 as a component of Red Hat Quay 3
  • quay/quay-rhel9 as a component of Red Hat Quay 3
Summary
A flaw was found in sanitize-html. Improper validation of the animation value attributes in SVG files allows an attacker to bypass scheme filters and embed a malicious script destination within a list of values. When a user interacts with the rendered SVG animation, the embedded script executes in the context of the application, leading to Cross-Site Scripting (XSS).
Remediation
To mitigate this vulnerability, ensure the allowedTags configuration does not contain any of the following elements: animate, animateColor, animateMotion, animateTransform or set.
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-2026-69654

No EUVD known-exploited evidence

ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From version 1.9.0 until version 2.17.7, packages/sanitize-html/index.js validates an animation value attribute as one flat URL and does not recognize that attributeName selecting href or xlink:href gives the sibling values, from, to, or by attribute SVG SMIL URL semantics. In configurations that allow the animate, animateColor, animateMotion, animateTransform, or set elements, a values list can begin with a safe fragment and contain a later executable destination that survives allowedSchemesAppliedToAttributes checking. When the sanitized SVG is rendered, the browser can copy that later destination into the live link, and a victim who activates the link can execute script in the application's origin. This issue is fixed in version 2.17.7.

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
5.4 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 16 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From version 1.9.0 until version 2.17.7, packages/sanitize-html/index.js validates an animation value attribute as one flat URL and does not recognize that attributeName selecting href or xlink:href gives the sibling values, from, to, or by attribute SVG SMIL URL semantics. In configurations that allow the animate, animateColor, animateMotion, animateTransform, or set elements, a values list can begin with a safe fragment and contain a later executable destination that survives allowedSchemesAppliedToAttributes checking. When the sanitized SVG is rendered, the browser can copy that later destination into the live link, and a victim who activates the link can execute script in the application's origin. This issue is fixed in version 2.17.7.

What

ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From version 1.9.0 until version 2.17.7, packages/sanitize-html/index.js validates an animation value attribute as one flat URL and does not recognize that attributeName selecting href or xlink:href gives the sibling values, from, to, or by attribute SVG SMIL URL semantics. In configurations that allow the animate, animateColor, animateMotion, animateTransform, or set elements, a values list can begin with a safe fragment and contain a later executable destination that survives allowedSchemesAppliedToAttributes checking. When the sanitized SVG is rendered, the browser can copy that later destination into the live link, and a victim who activates the link can execute script in the application's origin. This issue is fixed in version 2.17.7.

Why

Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From version 1.9.0 until version 2.17.7, packages/sanitize-html/index.js validates an animation value attribute as one flat URL and does not recognize that attributeName selecting href or xlink:href gives the sibling values, from, to, or by attribute SVG SMIL URL semantics. In configurations that allow the animate, animateColor, animateMotion, animateTransform, or set elements, a values list can begin with a safe fragment and contain a later executable destination that survives allowedSchemesAppliedToAttributes checking. When the sanitized SVG is rendered, the browser can copy that later destination into the live link, and a victim who activates the link can execute script in the application's origin. This issue is fixed in version 2.17.7.

Why

Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.

How

An attacker operating through a network path may attempt exploitation with low privileges. 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.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-79 ↗

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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:L/PR:L/UI:R/S:C/C:L/I:L/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.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SChangedScope: The attack can affect a component governed by a different security authority.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited 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.
NetworkCWE-79
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-69654Official EUVD mapping

ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From version 1.9.0 until version 2.17.7, packages/sanitize-html/index.js validates an animation value attribute as one flat URL and does not recognize that attributeName selecting href or xlink:href gives the sibling values, from, to, or by attribute SVG SMIL URL semantics. In configurations that allow the animate, animateColor, animateMotion, animateTransform, or set elements, a values list can begin with a safe fragment and contain a later executable destination that survives allowedSchemesAppliedToAttributes checking. When the sanitized SVG is rendered, the browser can copy that later destination into the live link, and a victim who activates the link can execute script in the application's origin. This issue is fixed in version 2.17.7.

Official EUVD record ↗
BSI · German · WID-SEC-2026-3596IBM App Connect Enterprise: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM App Connect Enterprise ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren und um einen Cross-Site Scripting Angriff durchzuführen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1256Multiples vulnérabilités dans les produits IBM

ord?id=CVE-2026-76172 Référence CVE CVE-2026-77063 https://www.cve.org/CVERecord?id=CVE-2026-77063 Référence CVE CVE-2026-77078 https://www.cve.org/CVERecord?id=CVE-2026-77078 Référence CVE CVE-2026-77310 https://www.cve.org/CVERecord?id=CVE-2026-77310 Référence CVE CVE-2026-82333 https://www.cve.org/CVERecord?id=CVE-2026-82333 Référence CVE CVE-2026-82417 https://www.cve.org/CVERecord?id=CVE-2026-82417 Référence CVE CVE-2026-8286 https://www.cve.org/CVERecord?id=CVE-2026-8286 Référence CVE CVE-2026-83557 https://www.cve.org/CVERecord?id=CVE-2026-83557 Référence CVE CVE-2026-84292 https://www.cve.org/CVERecord?id=CVE-2026-84292 Référence CVE CVE-2026-84371 https://www.cve.org/CVERecord?id=CVE-2026-84371 Référence CVE CVE-2026-84375 https://www.cve.org/CVERecord?id=CVE-2026-84375 Référence CVE CVE-2026-85061 https://www.cve.org/CVERecord?id=CVE-2026-85061 Référence CVE CVE-2026-8723 https://www.cve.org/CVERecord?id=CVE-2026-8723 Référence CVE CVE-2026-8763 https://www.cve.org/CVERecord?id=CVE-2026-8763 Référence CVE CVE-2026-9323 https://www.cve.org/CVERecord?id=CVE-2026-9323 Référence CVE CVE-2026-9358 https://www.cve.org/CVERecord?id=CVE-2026-9358 Gestion détaillée du document le 02 octobre 2026 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propo

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.
Fix availability varies by product
Affected
Fixed
2.17.7.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
To mitigate this vulnerability, ensure the allowedTags configuration does not contain any of the following elements: animate, animateColor, animateMotion, animateTransform or set.
04

Evidence and provenance

Published 1 Sept 2026 · Last source change 2 Sept 2026, 16:02 UTC · CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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 2026-09-02
European sourceENISA EUVD · EUVD-2026-69654
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD not scheduled

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

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    costmanagement/costmanagement-ui-rhel10 as a component of Cost Management On Premise; multicluster-engine/console-mce-rhel9 as a component of Multicluster Engine for Kubernetes; rhacm2/console-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; cockpit-image-builder as a component of Red Hat Enterprise Linux 10; cockpit-image-builder.src as a component of Red Hat Enterprise Linux 10; prometheus3.5.src as a component of Red Hat Hardened Images; rhoai/odh-mlflow-rhel9 as a component of Red Hat OpenShift AI (RHOAI); openshift4/ose-agent-installer-ui-rhel9 as a component of Red Hat OpenShift Container Platform 4; openshift4/ose-console as a component of Red Hat OpenShift Container Platform 4; openshift4/ose-console-rhel9 as a component of Red Hat OpenShift Container Platform 4; devspaces/dashboard-rhel9 as a component of Red Hat OpenShift Dev Spaces; quay/quay-rhel8 as a component of Red Hat Quay 3; quay/quay-rhel9 as a component of Red Hat Quay 3; nodejs-sanitize-html.src as a component of Red Hat Satellite 6; satellite/iop-advisor-frontend-rhel9 as a component of Red Hat Satellite 6; satellite/iop-host-inventory-frontend-rhel9 as a component of Red Hat Satellite 6; satellite/iop-vulnerability-frontend-rhel9 as a component of Red Hat Satellite 6
    After
    costmanagement/costmanagement-ui-rhel10 as a component of Cost Management On Premise; multicluster-engine/console-mce-rhel9 as a component of Multicluster Engine for Kubernetes; rhacm2/console-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; cockpit-image-builder as a component of Red Hat Enterprise Linux 10; cockpit-image-builder.src as a component of Red Hat Enterprise Linux 10; rhoai/odh-mlflow-rhel9 as a component of Red Hat OpenShift AI (RHOAI); openshift4/ose-agent-installer-ui-rhel9 as a component of Red Hat OpenShift Container Platform 4; openshift4/ose-console as a component of Red Hat OpenShift Container Platform 4; openshift4/ose-console-rhel9 as a component of Red Hat OpenShift Container Platform 4; devspaces/dashboard-rhel9 as a component of Red Hat OpenShift Dev Spaces; quay/quay-rhel8 as a component of Red Hat Quay 3; quay/quay-rhel9 as a component of Red Hat Quay 3; nodejs-sanitize-html.src as a component of Red Hat Satellite 6; satellite/iop-advisor-frontend-rhel9 as a component of Red Hat Satellite 6; satellite/iop-host-inventory-frontend-rhel9 as a component of Red Hat Satellite 6; satellite/iop-vulnerability-frontend-rhel9 as a component of Red Hat Satellite 6
    Red Hat Product Security ↗
  2. ENISA EUVD mappingEUVD-2026-69654 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-69654"}
    ENISA EUVD ↗
  3. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-69654↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference · GitHub GHSA-G8QQ-57P8-GGW5↗Official CVE record (CNA and ADP data)↗NVD record↗
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-2026-84371 · cve.blacktree.nl