What is CVE-2019-12991?

CVE-2019-12991 is a high-severity vulnerability in Citrix Netscaler Sd-Wan, classified under OS Command Injection. CVSS score: 8.8/10. Published 2019-07-16.

How severe is CVE-2019-12991?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2019-12991 known to be exploited?

Yes. CVE-2019-12991 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-25), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.

RCE in Citrix Netscaler Sd-Wan

CVE-2019-12991

Citrix SD-WAN 10.2.x before 10.2.3 and NetScaler SD-WAN 10.0.x before 10.0.8 have Improper Input Validation (issue 5 of 6).

Vulnerability class: Command Injection (OS Command Injection)

Published 2019-07-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.745 (99.5th percentile), scored 2026-10-19.

High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.741 · newest: 0.745 · change: +0.004

Affected products

Weakness classification (CWE)

CWE-78 — OS Command Injection

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2022-03-25. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-04-15.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

www.tenable.com/security/research/tra-2019-32 (Exploit, Third Party Advisory)
www.securityfocus.com/bid/109133 (VDB Entry, Third Party Advisory, vdb-entry, Broken Link)
packetstormsecurity.com/files/153638/Citrix-SD-WAN-Appliance-10.2.2-Authenticat… (Exploit, VDB Entry, Third Party Advisory)
support.citrix.com/article/CTX251987 (Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2019-12991?: CVE-2019-12991 is a high-severity vulnerability in Citrix Netscaler Sd-Wan, classified under OS Command Injection. CVSS score: 8.8/10. Published 2019-07-16.
How severe is CVE-2019-12991?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2019-12991 known to be exploited?: Yes. CVE-2019-12991 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-25), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.