What is CVE-2019-13608?

CVE-2019-13608 is a high-severity vulnerability in Citrix Storefront Server, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 7.5/10. Published 2019-08-29.

How severe is CVE-2019-13608?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2019-13608 known to be exploited?

Yes. CVE-2019-13608 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.

XXE in Citrix Storefront Server

CVE-2019-13608

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 class: XXE (XML External Entity)

Published 2019-08-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.300 (98.2th percentile), scored 2026-10-18.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 98.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.300 · newest: 0.300 · change: 0.000

Affected products

Citrix Storefront Server

Weakness classification (CWE)

CWE-611 — Improper Restriction of XML External Entity Reference (XXE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2021-11-03. 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: 2022-05-03.

Required action: Apply updates per vendor instructions.

Known ransomware campaign use: yes.

Public proof-of-concept exploits

References

support.citrix.com/article/CTX251988 (Mitigation, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2019-13608?: CVE-2019-13608 is a high-severity vulnerability in Citrix Storefront Server, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 7.5/10. Published 2019-08-29.
How severe is CVE-2019-13608?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2019-13608 known to be exploited?: Yes. CVE-2019-13608 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.