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Full vulnerability report · 2026
CVE-2026-25500High confidence

Rack's Stored XSS in Rack::Directory via javascript: filenames rendered into anchor href

rack · rack

Official source article: GitHub GHSA-WHRJ-4476-WVMP ↗. 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 public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 50 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:High, raised one band.upgradedsince 18 Feb 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • EPSS is 0.27% 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.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs rack rack 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: 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.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 50 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

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

5 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 · sourceruby-rackVendor fix publishedDebian records a fixed source-package version for this release.3.1.20-0+deb13u1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourceruby-rackVendor fix publishedDebian records a fixed source-package version for this release.2.2.22-0+deb12u1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourceruby-rackVendor fix publishedDebian records a fixed source-package version for this release.3.2.5-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourceruby-rackVendor fix publishedDebian records a fixed source-package version for this release.3.2.5-1Debian Security Tracker ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiveruby-rackVendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.2.2.7-1ubuntu0.6Canonical Ubuntu Security ↗Source updated 5 Oct 2026
Open-source package ranges6 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
RubyGemsrackECOSYSTEM: introduced 0; fixed 2.2.222.2.22OSV record ↗aggregator derived · 10 Sep 2026
RubyGemsrackECOSYSTEM: introduced 3.0.0.beta1; fixed 3.1.203.1.20OSV record ↗aggregator derived · 10 Sep 2026
RubyGemsrackECOSYSTEM: introduced 3.2.0; fixed 3.2.53.2.5OSV record ↗aggregator derived · 10 Sep 2026
rubygemsrack< 2.2.222.2.22GitHub advisory ↗upstream repository advisory · 10 Mar 2026
rubygemsrack>= 3.0.0.beta1, < 3.1.203.1.20GitHub advisory ↗upstream repository advisory · 10 Mar 2026
rubygemsrack>= 3.2.0, < 3.2.53.2.5GitHub advisory ↗upstream repository advisory · 10 Mar 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-2026-25500 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityrubygem-rack: Rack stored XSS in Rack::Directory
50 known affected

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

  • openshift-logging/cluster-logging-operator-bundle as a component of Logging Subsystem for Red Hat OpenShift
  • openshift-logging/cluster-logging-rhel9-operator as a component of Logging Subsystem for Red Hat OpenShift
  • openshift-logging/eventrouter-rhel9 as a component of Logging Subsystem for Red Hat OpenShift
  • openshift-logging/fluentd-rhel9 as a component of Logging Subsystem for Red Hat OpenShift
  • openshift-logging/log-file-metric-exporter-rhel9 as a component of Logging Subsystem for Red Hat OpenShift
  • openshift-logging/logging-view-plugin-rhel9 as a component of Logging Subsystem for Red Hat OpenShift
  • openshift-logging/vector-rhel9 as a component of Logging Subsystem for Red Hat OpenShift
  • 3scale-amp2/backend-rhel7 as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp2/backend-rhel8 as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp2/system-rhel7 as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp2/system-rhel8 as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp2/system-rhel9 as a component of Red Hat 3scale API Management Platform 2
Summary
A cross site scripting vulnerability has been discovered in the rubygem Rack. Rack::Directory generates an HTML directory index where each file entry is rendered as a clickable link. If a file exists on disk whose basename begins with the javascript: scheme (e.g. javascript:alert(1)), the generated index includes an anchor whose href attribute is exactly javascript:alert(1). Clicking this entry executes arbitrary JavaScript in the context of the hosting application. This results in a client-side XSS condition in directory listings generated by Rack::Directory.
Remediation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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-2026-7916

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 actionPatch only the product branches with a verified fix

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 50 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

Rack is a modular Ruby web server interface. Prior to versions 2.2.22, 3.1.20, and 3.2.5, `Rack::Directory` generates an HTML directory index where each file entry is rendered as a clickable link. If a file exists on disk whose basename starts with the `javascript:` scheme (e.g. `javascript:alert(1)`), the generated index contains an anchor whose `href` is exactly `javascript:alert(1)`. Clicking the entry executes JavaScript in the browser (demonstrated with `alert(1)`). Versions 2.2.22, 3.1.20, and 3.2.5 fix the issue.

What

Rack is a modular Ruby web server interface. Prior to versions 2.2.22, 3.1.20, and 3.2.5, `Rack::Directory` generates an HTML directory index where each file entry is rendered as a clickable link. If a file exists on disk whose basename starts with the `javascript:` scheme (e.g. `javascript:alert(1)`), the generated index contains an anchor whose `href` is exactly `javascript:alert(1)`. Clicking the entry executes JavaScript in the browser (demonstrated with `alert(1)`). Versions 2.2.22, 3.1.20, and 3.2.5 fix the issue.

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

Rack is a modular Ruby web server interface. Prior to versions 2.2.22, 3.1.20, and 3.2.5, `Rack::Directory` generates an HTML directory index where each file entry is rendered as a clickable link. If a file exists on disk whose basename starts with the `javascript:` scheme (e.g. `javascript:alert(1)`), the generated index contains an anchor whose `href` is exactly `javascript:alert(1)`. Clicking the entry executes JavaScript in the browser (demonstrated with `alert(1)`). Versions 2.2.22, 3.1.20, and 3.2.5 fix the issue.

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.
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 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-79Public 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-2026-0881IBM License Metric Tool: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM License Metric Tool ausnutzen, um Informationen offenzulegen, einen Cross Site Scripting Angriff durchzuführen oder einen Denial of Service zu verursachen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260225Security Bulletin 25 Feb 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 25 Feb 2026, published on 25 February 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0326Multiples vulnérabilités dans les produits VMware

rd?id=CVE-2026-2391 Référence CVE CVE-2026-23949 https://www.cve.org/CVERecord?id=CVE-2026-23949 Référence CVE CVE-2026-23950 https://www.cve.org/CVERecord?id=CVE-2026-23950 Référence CVE CVE-2026-24001 https://www.cve.org/CVERecord?id=CVE-2026-24001 Référence CVE CVE-2026-24049 https://www.cve.org/CVERecord?id=CVE-2026-24049 Référence CVE CVE-2026-24051 https://www.cve.org/CVERecord?id=CVE-2026-24051 Référence CVE CVE-2026-24733 https://www.cve.org/CVERecord?id=CVE-2026-24733 Référence CVE CVE-2026-24734 https://www.cve.org/CVERecord?id=CVE-2026-24734 Référence CVE CVE-2026-24842 https://www.cve.org/CVERecord?id=CVE-2026-24842 Référence CVE CVE-2026-25500 https://www.cve.org/CVERecord?id=CVE-2026-25500 Référence CVE CVE-2026-25639 https://www.cve.org/CVERecord?id=CVE-2026-25639 Référence CVE CVE-2026-25679 https://www.cve.org/CVERecord?id=CVE-2026-25679 Référence CVE CVE-2026-25702 https://www.cve.org/CVERecord?id=CVE-2026-25702 Référence CVE CVE-2026-25749 https://www.cve.org/CVERecord?id=CVE-2026-25749 Référence CVE CVE-2026-26007 https://www.cve.org/CVERecord?id=CVE-2026-26007 Référence CVE CVE-2026-26157 https://www.cve.org/CVERecord?id=CVE-2026-26157 Référence CVE CVE-2026-26158 https://www.cve.org/CVERecord?id=CVE-2026-26158 Référence CVE CVE-2026-26269 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0316Multiples vulnérabilités dans les produits VMware

d?id=CVE-2026-23237 Référence CVE CVE-2026-23238 https://www.cve.org/CVERecord?id=CVE-2026-23238 Référence CVE CVE-2026-23239 https://www.cve.org/CVERecord?id=CVE-2026-23239 Référence CVE CVE-2026-23240 https://www.cve.org/CVERecord?id=CVE-2026-23240 Référence CVE CVE-2026-23745 https://www.cve.org/CVERecord?id=CVE-2026-23745 Référence CVE CVE-2026-23950 https://www.cve.org/CVERecord?id=CVE-2026-23950 Référence CVE CVE-2026-24001 https://www.cve.org/CVERecord?id=CVE-2026-24001 Référence CVE CVE-2026-24051 https://www.cve.org/CVERecord?id=CVE-2026-24051 Référence CVE CVE-2026-24842 https://www.cve.org/CVERecord?id=CVE-2026-24842 Référence CVE CVE-2026-25500 https://www.cve.org/CVERecord?id=CVE-2026-25500 Référence CVE CVE-2026-25679 https://www.cve.org/CVERecord?id=CVE-2026-25679 Référence CVE CVE-2026-25702 https://www.cve.org/CVERecord?id=CVE-2026-25702 Référence CVE CVE-2026-25749 https://www.cve.org/CVERecord?id=CVE-2026-25749 Référence CVE CVE-2026-26007 https://www.cve.org/CVERecord?id=CVE-2026-26007 Référence CVE CVE-2026-26157 https://www.cve.org/CVERecord?id=CVE-2026-26157 Référence CVE CVE-2026-26158 https://www.cve.org/CVERecord?id=CVE-2026-26158 Référence CVE CVE-2026-26269 https://www.cve.org/CVERecord?id=CVE-2026-26269 Référence CVE CVE-2026-26960 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-004338Rackにおけるクロスサイトスクリプティングの脆弱性

Rackはモジュール式のRubyウェブサーバーインターフェースです。バージョン2.2.22、3.1.20、および3.2.5より前のバージョンでは、`Rack::Directory`は各ファイルエントリをクリック可能なリンクとしてレンダリングするHTMLディレクトリインデックスを生成します。ディスク上にベースネームが`javascript:`スキームで始まるファイル（例：`javascript:alert(1)`）が存在する場合、生成されたインデックスには`href`が正確に`javascript:alert(1)`となっているアンカーが含まれます。このエントリをクリックするとブラウザ内でJavaScriptが実行されます（`alert(1)`を用いて実証済みです）。バージョン2.2.22、3.1.20、および3.2.5でこの問題は修正されました。

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
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
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
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
04

Evidence and provenance

Published 18 Feb 2026 · Last source change 18 Feb 2026, 19:42 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 2026-08-14
European sourceENISA EUVD · EUVD-2026-7916
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.

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
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-7916↗Vendor CSAF · Red Hat Product Security↗Public exploit reference · GitHub GHSA-WHRJ-4476-WVMP↗Patch or update reference↗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-2026-25500 · cve.blacktree.nl