Out-of-bounds Read in Claris Filemaker Server

CVE-2026-86930

An out-of-bounds read vulnerability in FileMaker Server for Linux allowed an attacker uploading a specially crafted image file to a container field to disclose process memory during thumbnail generation in FileMaker WebDirect. This vulnerability is addressed in FileMaker Server version 26.0.3.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (21.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 21.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-86930: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-86930?
CVE-2026-86930 is a critical-severity vulnerability in Claris Filemaker Server, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-09-23.
How severe is CVE-2026-86930?
Critical severity. CVSS v3 base score is 9.1 out of 10.