All vulnerabilities
CVE-2026-100389

GestSup before 3.2.62 Remote Code Execution via IMAP Attachment

GestSup GestSup
Open in ThreatlineRecord JSON
CVSS
9.2Critical
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.58%Chance of exploitation activity in the next 30 days, higher than 47% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in3.2.62Fixed versionCVE List
Published25 Sep 2026Updated 30 Sep 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

GestSup versions before 3.2.62 contain a remote code execution vulnerability in the basic IMAP connector's attachment handling that fails to skip blocked file extensions. Unauthenticated attackers can send emails with PHP attachments to monitored mailboxes, which are written to the web-accessible upload/ticket directory and executed when accessed.

Text from CVE List

Affected versions 1

  • GestSupaffected: all versions before 3.2.62CVE List

References 4