Pass-through of unvalidated KMS URLs to KMS clients in Apache C++ Parquet and PyArrow versions 4.0.0 to 25.0.1.
This affects users who read Parquet files and configure Parquet decryption properties with a KmsClient implementation.
On the reader side, the KMS URL can be application-controlled (specified in the KmsConnectionConfig) 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 KMS implementation does not perform host validation and makes use of the provided KMS URL, a KMS token can be sent to a malicious host set by an attacker in the file.
Users are recommended to upgrade to version 26.0.0, which disables this behavior by default and requires that users opt-in to it by enabling the read_kms_url flag in the DecryptionConfiguration. Users of affected versions are recommended to either specify the KMS URL in the KmsConnectionConfig when reading files, or ensure any KmsClient implementations validate received KMS URLs. Users that opt-in to file-controlled KMS URLs in version 26.0.0 and later must ensure KmsClients validate KMS URLs.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
- EG Severity
- Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-20). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the BOD 26-04 block below.
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it