Description
Server-Side Request Forgery (SSRF) in Avro SerDe schema resolution in Apache Hive before 4.2.1 allows an authenticated remote attacker with CREATE TABLE privilege to cause the Hive server to fetch an attacker-controlled URL when resolving the avro.schema.url table property on an Avro table that is subsequently queried. This can expose cloud instance metadata, internal network services, or local server files to the Hive process identity. Users are recommended to upgrade to version 4.2.1, which fixes this issue.



Attacker access requirements:

* Network access to HiveServer2 / Metastore: required (remote attacker model).
* Valid Hive authentication: required.
* CREATE TABLE (or equivalent) privilege: required, so the attacker can set avro.schema.url in table properties.
* SELECT privilege on the malicious table: not required for the creator, who can typically query their own table; any other user granted SELECT can also trigger the fetch.
* Write access to the table LOCATION: not required; the attack uses the schema URL, not the data path.
* Admin / superuser privileges: not required; an ordinary authenticated user with DDL rights is sufficient.
* External tables enabled: typically required in practice, and enabled by default in most deployments.




Detection guidance:

* Inspect metastore / Hive table metadata for Avro tables whose avro.schema.url uses unexpected schemes such as http, https, file, or ftp, or points at link-local / cloud metadata addresses (for example 169.254.169.254) or other internal hosts.
* Review HiveServer2 and Metastore logs around CREATE/ALTER TABLE and queries against Avro tables for schema-resolution failures or outbound fetches of avro.schema.url.
* Correlate CREATE TABLE / ALTER TABLE activity that sets avro.schema.url with subsequent SELECT activity on the same table, especially when the URL target is unusual for schema distribution.
* On cloud deployments, check instance / VPC flow logs and metadata service access logs for unexpected requests from Hive host identities shortly after Avro DDL or query activity.
Published: 2026-08-25
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

This vulnerability describes Server‑Side Request Forgery in the Avro Serializer/Deserializer component of Apache Hive. Insufficient validation of the avro.schema.url property allows an authenticated user with CREATE TABLE privileges to cause the Hive server to fetch an attacker‑controlled URL during schema resolution. The request is made by the Hive process, so the contents of the URL—including cloud‑instance metadata, internal network services, or local files—can be exposed to the Hive server account, leading to confidentiality compromise. This weakness is identified as CWE‑918.

Affected Systems

All installations of Apache Hive that are older than version 4.2.1, running the HiveServer2 or Metastore components, are affected. Users of the Apache Software Foundation’s Hive product should verify that they are on version 4.2.1 or later. If a deployment uses earlier Hive releases, the vulnerability remains present until an upgrade or mitigation is applied.

Risk and Exploitability

The flaw requires an attacker to have network connectivity to the HiveServer2 or Metastore service and valid Hive authentication. An ordinary user possessing DDL rights is sufficient to set avro.schema.url; no administrative privileges are needed. Once the attacker creates or alters a table, any subsequent SELECT on that table by the same or other users will trigger the outbound fetch, which can be used to access internal resources such as 169.254.169.254 in cloud environments or other internal hosts. The EPSS score is not available, and the vulnerability has not yet been listed in the CISA KEV catalog, but the potential to expose sensitive data gives it a high impact. The lack of public exploitation data suggests a lower current exploitation probability, but the high consequence warrants immediate attention.

Generated by OpenCVE AI on August 25, 2026 at 11:20 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade Apache Hive to version 4.2.1 or later to address the SSRF issue.
  • Restrict the allowed schemes for avro.schema.url by configuring Hive to accept only trusted domains or protocols, effectively implementing a whitelist.
  • Limit CREATE TABLE privileges to a least‑privilege set of users and regularly audit table creation and schema changes in Hive metadata tables.
  • Monitor HiveServer2 and Metastore logs for abnormal outbound requests and consider blocking external traffic from HiveServer2 using network ACLs or firewalls as an additional safeguard.

Generated by OpenCVE AI on August 25, 2026 at 11:20 UTC.

Tracking

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Advisories

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History

Tue, 25 Aug 2026 10:30:00 +0000

Type Values Removed Values Added
Description Server-Side Request Forgery (SSRF) in Avro SerDe schema resolution in Apache Hive before 4.2.1 allows an authenticated remote attacker with CREATE TABLE privilege to cause the Hive server to fetch an attacker-controlled URL when resolving the avro.schema.url table property on an Avro table that is subsequently queried. This can expose cloud instance metadata, internal network services, or local server files to the Hive process identity. Users are recommended to upgrade to version 4.2.1, which fixes this issue. Attacker access requirements: * Network access to HiveServer2 / Metastore: required (remote attacker model). * Valid Hive authentication: required. * CREATE TABLE (or equivalent) privilege: required, so the attacker can set avro.schema.url in table properties. * SELECT privilege on the malicious table: not required for the creator, who can typically query their own table; any other user granted SELECT can also trigger the fetch. * Write access to the table LOCATION: not required; the attack uses the schema URL, not the data path. * Admin / superuser privileges: not required; an ordinary authenticated user with DDL rights is sufficient. * External tables enabled: typically required in practice, and enabled by default in most deployments. Detection guidance: * Inspect metastore / Hive table metadata for Avro tables whose avro.schema.url uses unexpected schemes such as http, https, file, or ftp, or points at link-local / cloud metadata addresses (for example 169.254.169.254) or other internal hosts. * Review HiveServer2 and Metastore logs around CREATE/ALTER TABLE and queries against Avro tables for schema-resolution failures or outbound fetches of avro.schema.url. * Correlate CREATE TABLE / ALTER TABLE activity that sets avro.schema.url with subsequent SELECT activity on the same table, especially when the URL target is unusual for schema distribution. * On cloud deployments, check instance / VPC flow logs and metadata service access logs for unexpected requests from Hive host identities shortly after Avro DDL or query activity.
Title Apache Hive: SSRF vulnerability in Hive Avro Serde due to Insufficient input validation on avro.schema.url
Weaknesses CWE-918
References

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2026-08-25T10:13:27.529Z

Reserved: 2026-06-17T23:57:13.013Z

Link: CVE-2026-55976

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-25T11:16:53.673

Modified: 2026-08-25T11:16:53.673

Link: CVE-2026-55976

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-25T11:30:06Z

Weaknesses
  • CWE-918

    Server-Side Request Forgery (SSRF)