How severe is CVE-2021-44145?

CVE-2021-44145 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-44145 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-44145?

CVE-2021-44145 affects Apache Nifi. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-44145?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-44145 published?

CVE-2021-44145 was published on 2021-12-17 and last updated on 2026-06-17.

CVE-2021-44145

CVE-2021-44145 is a medium-severity vulnerability in Apache Nifi with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Apache Nifi
Published: 2021-12-17
Last modified: 2026-06-17

Description

In the TransformXML processor of Apache NiFi before 1.15.1 an authenticated user could configure an XSLT file which, if it included malicious external entity calls, may reveal sensitive information.

Frequently asked questions

What is CVE-2021-44145?: In the TransformXML processor of Apache NiFi before 1.15.1 an authenticated user could configure an XSLT file which, if it included malicious external entity calls, may reveal sensitive information.
How severe is CVE-2021-44145?: CVE-2021-44145 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-44145 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-44145?: CVE-2021-44145 affects Apache Nifi. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-44145?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-44145 published?: CVE-2021-44145 was published on 2021-12-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:apache:nifi:*:*:*:*:*:*:*:*

More vulnerabilities in Apache Nifi

CVE-2018-1309 — Critical (CVSS 9.8): Apache NiFi External XML Entity issue in SplitXML processor. Malicious XML content could cause information disclosure…
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