CVE-2026-18090 and is rated Medium severity with a CVSS score of 6.1. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
What to do next
Remediation and response
Microsoft Security Response Center guidance
Vendor revision: Sep 24, 2026
Release Notes
CISA KEVNot listedBased on the latest collected catalog
EPSS0.2%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-18090?
A flaw was found in gdk-pixbuf. This vulnerability allows a remote attacker to cause a heap out-of-bounds read by providing a specially crafted Apple Icon Image (.icns) file.
The uncompress() function, which handles RLE-encoded ICNS icon data, fails to validate the source buffer's boundaries during decompression. This can lead to a denial of service, where the application crashes, or to information disclosure, potentially revealing sensitive data from adjacent memory.