CVE-2026-53561: Apache Hive: Unauthenticated authentication bypass in HiveServer2 HTTP SAML bearer-token validation allows impersonation of any Hive user
An improper authentication vulnerability in HiveServer2 SAML bearer-token validation in Apache Hive 4.0.0 through 4.2.0 (and later unreleased branches) on deployments using HTTP transport with hive.server2.authentication=SAML allows an unauthenticated network attacker to authenticate as an arbitrary Hive user and obtain an authenticated HiveServer2 session via a forged Authorization: Bearer token sent to the /cliservice HTTP endpoint. Users are recommended to upgrade to 4.2.1 version that includes the fix for this issue.
Access / authorization required: No Hive credentials, SAML IdP login, or knowledge of the server signing secret is required. The attacker only needs network reachability to the HiveServer2 HTTP port (typically /cliservice), directly or through a reverse proxy such as Apache Knox that forwards unauthenticated requests to HS2. The instance must have SAML authentication enabled in HTTP mode. Deployments where Knox handles SSO and HiveServer2 uses LDAP/Kerberos (not native SAML mode) are not affected by this specific issue.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Apache Hiveto a version that resolves this vulnerability.Fixed in 4.2.1
Event History
Frequently Asked Questions
Which deployments are affected?
Affected deployments run Apache Hive 4.0.0 through 4.2.0, use HiveServer2 HTTP transport, and set hive.server2.authentication=SAML. The vulnerable endpoint is the HiveServer2 /cliservice HTTP endpoint.
What does an attacker need to exploit this issue?
An attacker needs only network reachability to the HiveServer2 HTTP port, either directly or through a reverse proxy that forwards unauthenticated requests to HiveServer2. No Hive credentials, SAML IdP login, or server signing secret are required.
Are deployments using Apache Knox affected?
A Knox deployment can be affected if it forwards unauthenticated requests to HiveServer2 running native SAML authentication in HTTP mode. Deployments where Knox performs SSO while HiveServer2 uses LDAP or Kerberos rather than native SAML mode are not affected by this specific issue.
What should administrators do?
Upgrade Apache Hive to version 4.2.1, which includes the fix. Until upgrading, restrict unauthenticated network access to the HiveServer2 HTTP endpoint and prevent reverse proxies from forwarding unauthenticated requests to it.