Vulnerability Database

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Total vulnerabilities in the database

CVE-2026-55976 — apache / hive

Server-Side Request Forgery (SSRF)

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: Aug 25, 2026
  • Updated: Sep 13, 2026
  • CVE: CVE-2026-55976
  • Severity: Critical
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Critical
  • Score: 9.1
  • AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CWEs:

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.