What is CVE-2018-1309?

CVE-2018-1309 is a critical-severity vulnerability in Apache Nifi, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 9.8/10. Published 2018-05-23.

How severe is CVE-2018-1309?

Critical severity. CVSS v3 base score is 9.8 out of 10.

XXE in Apache Nifi

CVE-2018-1309

Apache NiFi External XML Entity issue in SplitXML processor. Malicious XML content could cause information disclosure or remote code execution. The fix to disable external general entity parsing and disallow doctype declarations was applied on the Apache NiFi 1.6.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

Vulnerability class: XXE (XML External Entity)

Published 2018-05-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.045 (91.4th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 91.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.045 · newest: 0.045 · change: 0.000

Affected products

Apache Nifi
Apache Software Foundation Nifi — versions 0.1.0 - 1.5.0

Weakness classification (CWE)

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

References

nifi.apache.org/security.html (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2018-1309?: CVE-2018-1309 is a critical-severity vulnerability in Apache Nifi, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 9.8/10. Published 2018-05-23.
How severe is CVE-2018-1309?: Critical severity. CVSS v3 base score is 9.8 out of 10.