What it is
CVE-2019-13608 is an unauthenticated vulnerability affecting Citrix StoreFront Server. Citrix StoreFront Server before 1903, 7.15 LTSR before CU4 (3.12.4000), and 7.6 LTSR before CU8 (3.0.8000) allows XXE attacks.
Vulnerability report
Active exploitation observed
Confirmed confidence
In CISA KEV
CVE-2019-13608
StoreFront Server
Citrix / StoreFront Server
- Severity
- CVSS 7.5 · High
- Confidence
- Confirmed
- Exploit status
- Observed in sensors
- EPSS
- 30.0%
- First observed
- 12 Jun 2026
- Last observed
- 12 Aug 2026
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.
Who is affected?
Citrix / StoreFront Server.
What should we do?
Patch immediately, validate internet-facing exposure, and monitor for matching requests.
Overview
StoreFront Server
Citrix StoreFront Server before 1903, 7.15 LTSR before CU4 (3.12.4000), and 7.6 LTSR before CU8 (3.0.8000) allows XXE attacks.
- Published
- 29 Aug 2019
- Exploitation Reported
- 03 Nov 2021
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
malware
ransomware
cisa
nuclei_scanner
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2019-13608
- support.citrix.com/article/CTX251988 support.citrix.com · CVE Record https://support.citrix.com/article/CTX251988
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CISA
Independent exploitation attestation added to the KEV Intelligence record.
Active exploitation observed
KEV Intelligence sensor
First-party sensor telemetry confirms matching exploitation attempts.
Used in malware
CISA
Malware families have been linked to exploitation of this CVE.
Proof of concept available
Nuclei Templates
Public scanner or PoC coverage increases practical exploitability.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2021-11-03 00:00 UTC |
| KEV Intelligence | 2026-07-03 11:17 UTC |
Operational indicators for this CVE are listed under Detection.
Sensor telemetry
First-party evidence of exploitation activity
Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.
2
Attempts observed
2
Unique attacker IPs
2
Attacker countries
US · VE
2
Sensors observed
Exploitation attempts over the last 70 days
Daily events observed by KEV Intelligence sensors
Updated 19 Aug 2026
11 Jun
25 Jun
9 Jul
23 Jul
19 Aug
First observed 12 Jun 2026 · Last observed 12 Aug 2026
Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 1
- User-Agents
- 2
Raw values available in Pro and Enterprise.
Scanner coverage
Nuclei template detected 01 Jun 2026.
View Nuclei template (opens in new tab)Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Attacker IP Indicators
Attacker IP indicators observed · available in Pro and Enterprise.
Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.
Learn about Pro API accessScanner Artifacts
Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2019/CVE-2019-13608.yaml | 01 Jun 2026 |
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
7.5
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
30.0%
All CVSS Scores
CVSS v3.1
7.5
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v2.0
5.0
Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
Citrix StoreFront Server - XML External Entity
nuclei · Created Unknown
Timeline
From disclosure to observed exploitation
-
Public PoC available
Public proof-of-concept code published
-
Observed by KEV Intelligence sensors
Evidence-backed exploitation signal
-
Indicators of compromise added (8)
Indicators of compromise recorded
-
Nuclei template available
Scanner coverage available
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
First public exploitation report
Exploit observed in malware
-
CVE published
Vulnerability disclosed publicly
-
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.
- 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-2019-13608
Free JSON includes basic KEV fields{
"cve_id": "CVE-2019-13608",
"confidence": "Confirmed",
"cvss_score": 7.5,
"cvss_estimated": false,
"epss_score": 0.30041,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "attempts": 2, "sensors": 2 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.