# CVE-2026-55976: Apache Hive: SSRF vulnerability in Hive Avro Serde due to Insufficient input validation on avro.schema.url

> Authenticated attackers with table creation privileges can trigger Server-Side Request Forgery via malicious Avro schema URLs, exposing internal services and cloud metadata.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Aug 2026
- **Updated:** 26 Aug 2026
- **Also known as:** CLEANSTART-2026-BJ90324, GHSA-gp8m-92x3-q87g

## What is CVE-2026-55976?

CVE-2026-55976 is a critical server-side request forgery vulnerability in Apache Hive, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-55976?

It affects 1 product.


Products: Apache Hive.

## How do I fix CVE-2026-55976?

Upgrade to a fixed version.

## Is CVE-2026-55976 being exploited?

There is no known exploitation of CVE-2026-55976 in the wild and no public exploit code.

## Other vulnerabilities in Apache Hive

- [CVE-2026-49845](https://insights.sbomify.com/CVE-2026-49845/): Apache Hive: SQL Injection vulnerability in HiveMetaStore partition-name direct-SQL paths (critical 9.8)
- [CVE-2018-21234](https://insights.sbomify.com/CVE-2018-21234/): Deserialization of Untrusted Data in Jodd (critical 9.8)
- [CVE-2018-1282](https://insights.sbomify.com/CVE-2018-1282/): SQL Injection in hive-jdbc (critical 9.1)
- [CVE-2022-41137](https://insights.sbomify.com/CVE-2022-41137/): Apache Hive: Deserialization of untrusted data when fetching partitions from the Metastore (high 8.3)
- [CVE-2015-7521](https://insights.sbomify.com/CVE-2015-7521/): High severity vulnerability that affects org.apache.hive:hive, org.apache.hive:hive-exec, and org.apache.hive:hive-service (high 8.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55976 and fix it if it is affected.

What it is: CVE-2026-55976 is a critical server-side request forgery vulnerability in Apache Hive, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-55976 in the wild and no public exploit code.

Affected product: Apache Hive. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55976/ (Markdown: https://insights.sbomify.com/CVE-2026-55976/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55976
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55976
- OSV: https://osv.dev/vulnerability/CVE-2026-55976

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-55976/
Summaries are generated and may contain mistakes; the official description above is the record.