Vulnerability report

Exploitation Attempts Observed in the Wild High Confidence Not in CISA KEV

CVE-2026-112356

GFI KerioConnect < 10.0.9p2 XSS Cross-Site Scripting

GFI USA / GFI KerioConnect · affected before 10.0.9p2

Watch CVE-2026-112356 Browse KEV feed
Severity
CVSS 5.1 · Medium
Confidence
High
Exploit status
Exploitation Attempts Observed in the Wild
EPSS
—
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-112356 is an unauthenticated vulnerability affecting GFI USA GFI KerioConnect. GFI KerioConnect (Kerio Connect) before 10.0.9 Patch 2 contains a cross-site scripting vulnerability in the Webmail component...

Have exploitation attempts been observed?

Yes. Exploitation attempts have been reported for this vulnerability. Previdian lists it as a known exploited vulnerability. Also reported by third-party sources. Confidence is high.

Who is affected?

GFI USA / GFI KerioConnect affected before 10.0.9p2.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

GFI KerioConnect < 10.0.9p2 XSS Cross-Site Scripting

GFI KerioConnect (Kerio Connect) before 10.0.9 Patch 2 contains a cross-site scripting vulnerability in the Webmail component that allows a remote attacker to spoof link targets or inject HTML into a message as rendered in a victim's authenticated Webmail session by sending a crafted email whose text is already inside a link.

Attackers can exploit the link auto-formatter's re-processing of already-linked text, using quote characters to break out of the href attribute and inject attacker-controlled markup to execute script in the victim's session.

GFI USA, LLC Affected
GFI KerioConnect
Before 10.0.9p2
View vendor advisory (opens in new tab)
Published
28 Oct 2026
Exploitation Attempts Reported
28 Oct 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
—

CVE References

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation Attempts Observed in the Wild

CVE

Recorded 28 Oct 2026

A trusted third party reported exploitation attempts.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CVE First 2026-10-28 15:31 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

5.1 Medium

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

EPSS

—

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE-79 Improper Neutralization of Script in Attributes in a Web Page CWE-83

All CVSS Scores

CVSS v4.0 5.1 Medium

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS v3.1 6.1 Medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Timeline

From disclosure to observed exploitation attempts

  1. 15:31 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party report of exploitation attempts

  2. 15:26 UTC

    CVE published

    Vulnerability disclosed publicly

  3. 14:41 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-112356

Sample API response 
{
  "cve_id": "CVE-2026-112356",
  "confidence": "High",
  "cvss_score": 5.1,
  "cvss_estimated": false,
  "epss_score": null,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}