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Matcha SnsApplication · Icz

CVE-2026-27787

MEDIUM · 5.4 CVSS v3.0 Published 2026-04-08
Fix available
A fix is available. Upgrade to after 1.3.9 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Cross-site scripting vulnerability exists in MATCHA SNS 1.3.9 and earlier. If this vulnerability is exploited, an arbitrary script may be executed on the web browser of the user who accessed the website using the product.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Cross-site scripting (XSS) vulnerability in MATCHA SNS 1.3.9 and earlier allows attackers to inject arbitrary JavaScript or HTML into web pages, which then executes in the browsers of users who visit affected pages. This occurs due to insufficient input validation and output encoding of user-supplied data rendered in web pages.

MitigationApply vendor-provided patch for MATCHA SNS to address input sanitization. Implement output encoding and input validation on all user-controlled data before rendering in HTML context. Consider deploying a WAF as interim protection until patch is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Matcha SnsApplication
Affected:<= 1.3.9

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm MATCHA SNS installation
    Locate the application files or check the web server for the presence of MATCHA SNS. Look for version information in the application footer, admin panel, or version file within the installation directory.
    Affected if MATCHA SNS version 1.3.9 or earlier is confirmed to be installed
  2. Determine exact version number
    Access the admin interface or check the source files for the version identifier. Compare the installed version against the affected range (<=1.3.9).
    Affected if Version is 1.3.9 or any earlier version number
  3. Verify user-generated content functionality
    Check if the application has features that accept user input such as posts, comments, user profiles, messages, or any content submission forms.
    Affected if The application accepts and stores user-submitted content that gets rendered to other users
  4. Confirm content is rendered without sanitization
    Submit a test payload containing HTML or script tags through the identified input fields (such as a post or profile field). Then view that content as a different user to observe if the injected code executes.
    Affected if User-supplied content is displayed to other users without proper output encoding/escaping

If MATCHA SNS version 1.3.9 or earlier is running and the application allows users to submit and view content, the environment is likely affected by this stored XSS vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 1.3.9
Interim mitigation

Apply vendor-provided patch for MATCHA SNS to address input sanitization. Implement output encoding and input validation on all user-controlled data before rendering in HTML context. Consider deploying a WAF as interim protection until patch is applied.

Recommended fix Moderate confidence

Version 1.4.0 or later (first version after 1.3.9)

  1. 1. Identify the current installed version of Matcha SNS by checking the application configuration or administration panel
  2. 2. Navigate to the official Matcha SNS distribution or repository (oss.icz.co.jp or similar official source)
  3. 3. Download the latest stable release version newer than 1.3.9
  4. 4. Back up the current Matcha SNS installation including database and configuration files
  5. 5. Deploy the new version, ensuring all configuration files are properly migrated
  6. 6. Verify the application functions correctly after upgrade
  7. 7. Test that the XSS vulnerability is no longer exploitable by reviewing the fixed code paths or using automated XSS scanning tools

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Matcha Sns Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27787 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data