CVE-2026-53561 is a high-severity (CVSS 7.4) Improper Authentication vulnerability. O3 Security confirms whether CVE-2026-53561 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Apache Hive: Unauthenticated authentication bypass in HiveServer2 HTTP SAML bearer-token validation allows impersonation of any Hive user
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-53561.
Description
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-53561 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-53561 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-53561. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-53561 in your dependencies?
O3 detects CVE-2026-53561 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.