CVE-2026-112353: GFI USA, LLC GFI KerioConnect (Medium, CVSS 6.2)

Remote Attacker
CVE-2026-112353MediumGFI USA, LLC GFI KerioConnect
CVSS
6.2 Medium (v4.0)
EPSS
0.2% chance of exploitation in the next 30 days (higher than 15.4% of CVEs)
Exploited in the wild
Not on CISA’s KEV list
Public exploit
None reported in public exploit databases
Weakness
CWE-79, CWE-83
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N
Published
Oct 27, 2026

What it is

GFI KerioConnect (Kerio Connect) before 10.0.8 Patch 2 contains a stored cross-site scripting vulnerability in the Webmail component that allows a remote attacker to run JavaScript in a victim's authenticated Webmail session by uploading a crafted SVG email attachment that bypasses sanitization of event-handler attributes. Attackers can exploit the temporary-download endpoint's insufficient Content-Security-Policy sandbox to execute scripts when the attachment is opened, enabling theft of the victim's credentials and mailbox contents. Proofpoint Threat Research has observed exploitation in the wild as a credential and mailbox stealer.

Description from the National Vulnerability Database.

What to do

Check whether you run GFI USA, LLC GFI KerioConnect, then apply the vendor’s fix or mitigation from the advisories below.

Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.