XSS in Gfi Usa, Llc Kerioconnect
CVE-2026-112353
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- gfi.ai/resource/kerioconnect-product-releases/ (release-notes, patch)
- www.vulncheck.com/advisories/gfi-kerioconnect-8p2-stored-xss-via-svg-attachment (third-party-advisory)
Frequently asked questions
- What is CVE-2026-112353?
- CVE-2026-112353 is a high-severity vulnerability in Gfi Usa, Llc Kerioconnect, classified under Cross-site Scripting. CVSS score: 8.2/10. Published 2026-10-27.
- How severe is CVE-2026-112353?
- High severity. CVSS v3 base score is 8.2 out of 10.