CVE-2026-55976 Apache Software Foundation CVE debrief

Who should care

Defenders responsible for Apache Hive deployments should assess exposure and prioritize upgrading to version 4.2.1 or later. They should also inspect metastore / Hive table metadata and review HiveServer2 and Metastore logs for suspicious activity.

Why it matters

This SSRF vulnerability in Apache Hive can allow an authenticated remote attacker to cause the Hive server to fetch an attacker-controlled URL, potentially exposing sensitive information. Defenders should prioritize upgrading to version 4.2.1 or later and monitor for suspicious activity.

• Potential exposure of cloud instance metadata, internal network services, or local server files to the Hive process identity
• Possible unauthorized access to sensitive information
• Need for verification of affected versions and remediation
• Potential for attackers to exploit this vulnerability to gain further access

Technical summary

The vulnerability exists in the Avro SerDe schema resolution in Apache Hive before version 4.2.1. An authenticated remote attacker with CREATE TABLE privilege can 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, potentially exposing cloud instance metadata, internal network services, or local server files to the Hive process identity. This requires network access to HiveServer2 / Metastore, valid Hive authentication, and CREATE TABLE privilege. Defenders should prioritize upgrading to version 4.2.1 or later and monitor for suspicious activity.

Defensive priority

Upgrade to version 4.2.1 or later to fix this issue. Inspect metastore / Hive table metadata for Avro tables whose avro.schema.url uses unexpected schemes or points at link-local / cloud metadata addresses. 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.

Recommended defensive actions

• Upgrade to version 4.2.1 or later
• Inspect metastore / Hive table metadata for suspicious Avro tables
• Review HiveServer2 and Metastore logs for schema-resolution failures or outbound fetches
• Verify affected Hive deployments exist in managed environments
• Plan vendor-supported updates or mitigations through normal change control
• Review compensating controls for exposed systems
• Track exceptions and retest remediated assets

Evidence notes

The CVE record and NVD vulnerability detail provide information on the SSRF vulnerability in Apache Hive. The vendor advisory and patch information are available from Apache. Defenders should verify affected versions, review HiveServer2 and Metastore logs, and inspect metastore / Hive table metadata for suspicious Avro tables. Evidence is based on CVE and NVD details, with limitations on source-provided information.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.