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Incorrect AuthorizationWeakness · CWE-863

CVE-2025-8533

MEDIUM · 6.9 CVSS v4.0 Published 2025-08-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
78/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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
A vulnerability was identified in the XPC services of Fantastical. The services failed to implement proper client authorization checks in its listener:shouldAcceptNewConnection method, unconditionally accepting requests from any local process. As a result, any local, unprivileged process could connect to the XPC service and access its methods. This issue has been resolved in version 4.0.16.

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

Fantastical's XPC services contained an authorization bypass in the listener:shouldAcceptNewConnection method, which failed to validate client identity and unconditionally accepted connections from any local process, allowing unprivileged local code to invoke XPC service methods.

MitigationUpdate Fantastical to version 4.0.16 or later, which implements proper client authorization checks in the XPC listener.

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

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
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 Fantastical is installed
    Check if /Applications/Fantastical.app exists, or run: ls /Applications/ | grep -i fantastical
    Affected if Fantastical is not found in /Applications
  2. Get installed Fantastical version
    Run: defaults read /Applications/Fantastical.app/Contents/Info.plist CFBundleShortVersionString
    Affected if Version cannot be determined or is below 4.0.16
  3. Compare version to fixed release
    Compare the obtained version number to 4.0.16 using standard version comparison (e.g., 4.0.15 < 4.0.16 < 4.0.16)
    Affected if Installed version is lower than 4.0.16 (e.g., 4.0.15, 4.0.14, etc.)
  4. Verify XPC service component exists
    Check for XPC service bundle within Fantastical.app: ls /Applications/Fantastical.app/Contents/XPCServices/ 2>/dev/null
    Affected if XPC service directory exists and version is below 4.0.16

A user is affected if Fantastical is installed with a version lower than 4.0.16, as the authorization bypass in the XPC listener affects all versions prior to the fix.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update Fantastical to version 4.0.16 or later, which implements proper client authorization checks in the XPC listener.

Recommended fix High confidence

Fantastical version 4.0.16

  1. Open Fantastical on your Mac
  2. Go to the Fantastical menu and select 'Check for Updates'
  3. If an update is available, download and install version 4.0.16 or later
  4. Restart Fantastical after the update completes

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $910
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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-2025-8533 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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