Auth bypass in Flexibits Fantastical
CVE-2025-8533
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.
Vulnerability class: Broken Access Control
Published · last modified .
EPSS exploit prediction
EPSS: 0.004 (30.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Flexibits Fantastical — versions 0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cert.pl/en/posts/2025/08/CVE-2025-8533 (third-party-advisory)
- flexibits.com/fantastical (product)
Frequently asked questions
- What is CVE-2025-8533?
- CVE-2025-8533 is a vulnerability in Flexibits Fantastical, classified under Incorrect Authorization. Published 2025-08-07.
- Is CVE-2025-8533 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.