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ConnectApplication · Adobe

CVE-2026-21331

MEDIUM · 6.1 CVSS v3.1 Published 2026-04-14
Fix available
A fix is available. Upgrade to 12.11 / 2025.9.15 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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
Adobe Connect versions 2025.3, 12.10 and earlier are affected by a reflected Cross-Site Scripting (XSS) vulnerability. If an attacker is able to convince a victim to visit a URL referencing a vulnerable page, malicious JavaScript content may be executed within the context of the victim's browser. Scope is changed.

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 · high confidence

Adobe Connect versions 2025.3, 12.10 and earlier contain a reflected Cross-Site Scripting (XSS) vulnerability. An attacker can craft a malicious URL containing JavaScript payloads that, when clicked by a victim, gets reflected back and executed in the victim's browser within the context of the Adobe Connect application. The CVSS scope is 'changed', indicating the vulnerability can impact resources outside the vulnerable component's security scope.

MitigationUpgrade to a patched version of Adobe Connect when available. In the interim, implement output encoding for all user-supplied input and configure Content-Security-Policy headers to mitigate XSS execution.

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
ConnectApplication
Affected:< 12.11
Connect Desktop ApplicationApplication
Affected:<= 2025.3< 2025.9.15

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
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/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. Check Adobe Connect version
    Access the Adobe Connect login page or admin interface and look for the version number, typically displayed in the footer or About section. Alternatively, check the installation directory for version metadata files.
    Affected if The installed version is 12.10 or earlier, or any version below 12.11
  2. Check Adobe Connect Desktop Application version
    Open the Desktop Application and navigate to Help > About, or check the installed programs list in the system control panel for the version number.
    Affected if The installed version is 2025.3 or earlier, or any version below 2025.9.15
  3. Verify if the web interface processes URL parameters
    Identify whether the Adobe Connect web application reflects URL parameters (query strings, path segments) back to the user without encoding, particularly in any custom modules or third-party integrations.
    Affected if User-supplied input from URL parameters is reflected in responses without proper output encoding

A user is affected if their Adobe Connect installation is version 12.10 or earlier (below 12.11) or their Desktop Application is version 2025.3 or earlier (below 2025.9.15), and the application reflects URL parameters to users without encoding.

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 12.11 / 2025.9.15 or later
Fixed in 12.112025.9.15
Interim mitigation

Upgrade to a patched version of Adobe Connect when available. In the interim, implement output encoding for all user-supplied input and configure Content-Security-Policy headers to mitigate XSS execution.

Recommended fix High confidence

Adobe Connect 12.11 or later; Connect Desktop Application 2025.9.15 or later

  1. Identify which Adobe Connect product is deployed: Adobe Connect server application or Connect Desktop Application
  2. For Adobe Connect server: upgrade to version 12.11 or later
  3. For Connect Desktop Application: upgrade to version 2025.9.15 or later
  4. After upgrading, verify the version number matches or exceeds the fixed release
  5. Confirm the XSS vulnerability is remediated by testing the previously vulnerable endpoint
Caveat Review Adobe's release notes for any compatibility or configuration changes between your current version and the target version

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

Fix this in Connect 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
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

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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-2026-21331 in production — separate from our analysis above.

No notes yet

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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