Is CVE-2019-11634 actively exploited?

Yes. Previdian tracks CVE-2019-11634 as a known exploited vulnerability. Confidence is confirmed.

What exploitation activity has Previdian observed?

Previdian has not yet recorded sensor-observed exploitation attempts for CVE-2019-11634. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

Version-level data is not available; Previdian tracks Citrix Workspace App.

Yes. CVE-2019-11634 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2019-11634

Workspace App

Citrix / Workspace App

Watch CVE-2019-11634 Browse KEV feed

Severity: CVSS 9.8 · Critical
Confidence: Confirmed
Exploit status: Exploited in the wild
EPSS: 8.1%
First observed: —
Last observed: —

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2019-11634 is an unauthenticated vulnerability affecting Citrix Workspace App. Citrix Workspace App before 1904 for Windows has Incorrect Access Control.

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Citrix / Workspace App.

What should we do?

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

Overview

Citrix Workspace App before 1904 for Windows has Incorrect Access Control

Citrix Workspace App before 1904 for Windows has Incorrect Access Control.

Published: 22 May 2019
Exploitation Reported: 03 Nov 2021
Attack vector: Remote
Complexity: Low
Privileges: None
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2019-11634
support.citrix.com/v1/search support.citrix.com · CVE Record https://support.citrix.com/v1/search?searchQuery=%22%22&lang=en&sort=...
support.citrix.com/article/CTX251986 support.citrix.com · CVE Record https://support.citrix.com/article/CTX251986

Exploitation evidence

Why Previdian 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

Recorded 03 Nov 2021

A trusted third party reported exploitation.

Used in malware

CISA

Recorded 03 Nov 2021

Malware families have been linked to exploitation of this CVE.

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
CISA First	2021-11-03 00:00 UTC
CVE	2026-08-12 04:20 UTC

Detection

Operational artifacts and observed signals

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

Observed signals

Request targets
User-Agents
Callback hosts: 0; 0; 0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

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 v3.1

9.8 Critical

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

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

EPSS

8.1%

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

Weaknesses

Improper Access Control CWE-284

All CVSS Scores

CVSS v3.1 9.8 Critical

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

CVSS v2.0 7.5 High

AV:N/AC:L/Au:N/C:P/I:P/A:P

Timeline

From disclosure to observed exploitation

12 Aug 2026
04:20 UTC

KEV confirmed by CVE

Exploitation attested by an external source
03 Nov 2021
00:00 UTC

Added to CISA KEV

Listed in the CISA Known Exploited Vulnerabilities catalog
03 Nov 2021
00:00 UTC

First public exploitation report

Exploit observed in malware
22 May 2019
16:46 UTC

CVE published

Vulnerability disclosed publicly
01 May 2019
00:00 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-2019-11634

Sample API response

{
  "cve_id": "CVE-2019-11634",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.08091,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}