How severe is CVE-2026-73334?

CVE-2026-73334 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-73334 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-73334?

CVE-2026-73334 affects Apache Parquet. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-73334?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-73334 published?

CVE-2026-73334 was published on 2026-09-09 and last updated on 2026-09-10.

CVE-2026-73334

CVE-2026-73334 is a high-severity vulnerability in Apache Parquet with a CVSS 3.x base score of 8.1. 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-20.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Apache Parquet
Published: 2026-09-09
Last modified: 2026-09-10

Description

Potential problem for users of the org.apache.parquet.crypto.keytools package in Apache Parquet, versions 1.12 to 1.18. This package enables users to encrypt Parquet files via an envelope encryption mechanism that wraps (encrypts) data keys via a Key Management Service (KMS). On the reader side, the KMS URL can be application-controlled or file-controlled. If the user does not leverage application control for this parameter, a file-controlled KMS URL is forwarded to a pluggable KmsClient implementation. If the pluggable implementation does not perform host validation, a KMS token can be sent to a malicious host set by an attacker in the file. Before the problem is fixed, users are recommended to leverage application control for KMS URL parameter in readers (versions 1.12-1.18). After the problem is fixed (presumably in version 1.19), the upgrade will disable file-controlled KMS URL by default. Users of the KMS URL parameter will have two options then: leverage application control for KMS URL parameter in readers, or enable file-controlled KMS URL (via a new app parameter). The latter option will explicitly require (in the new parameter documentation) to validate the KMS URL and use authentication in the custom implementation of the KMS client plug in.

Frequently asked questions

What is CVE-2026-73334?: Potential problem for users of the org.apache.parquet.crypto.keytools package in Apache Parquet, versions 1.12 to 1.18. This package enables users to encrypt Parquet files via an envelope encryption mechanism that wraps (encrypts) data keys via a Key Management Service (KMS). On the reader side, the KMS URL can be application-controlled or file-controlled. If the user does not leverage application control for this parameter, a file-controlled KMS URL is forwarded to a pluggable KmsClient implementation. If the pluggable implementation does not perform host validation, a KMS token can be sent to a malicious host set by an attacker in the file. Before the problem is fixed, users are recommended to leverage application control for KMS URL parameter in readers (versions 1.12-1.18). After the problem is fixed (presumably in version 1.19), the upgrade will disable file-controlled KMS URL by default. Users of the KMS URL parameter will have two options then: leverage application control for KMS URL parameter in readers, or enable file-controlled KMS URL (via a new app parameter). The latter option will explicitly require (in the new parameter documentation) to validate the KMS URL and use authentication in the custom implementation of the KMS client plug in.
How severe is CVE-2026-73334?: CVE-2026-73334 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-73334 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-73334?: CVE-2026-73334 affects Apache Parquet. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-73334?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-73334 published?: CVE-2026-73334 was published on 2026-09-09 and last updated on 2026-09-10.

References

Affected products (1)

cpe:2.3:a:apache:parquet:*:*:*:*:*:*:*:*

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