CVE-2026-42811

Estado: AnalizadaCrítica (9.4)—

In plain terms, Apache Polaris is supposed to issue short-lived GCS credentials that only work for one table's files, but a crafted namespace or table name can cause those credentials to work across the configured bucket instead.

Apache Polaris builds Google Cloud Storage downscoped credentials by creating a Credential Access Boundary (CAB) with CEL conditions that are intended to restrict access to the requested table's storage path.

The relevant CEL string is built from the bucket name and the table path. That table path is derived from namespace and table identifiers. In current code, that path appears to be inserted into the CEL expression without escaping.

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As a result, a namespace or table identifier containing a single quote and other URI-safe CEL fragments can break out of the intended quoted string and change the meaning of the CEL condition.

In private testing against Polaris 1.4.0 on real Google Cloud Storage, it was confirmed that Polaris accepted a crafted identifier and returned delegated GCS credentials whose CEL path restriction had effectively collapsed.

Those delegated credentials could then:

- and also list, read, create, and delete objects under an unrelated external prefix in the same bucket that was not part of any table path.

That last point is important. The issue is not limited to "another table". In the confirmed setup, once Apache Polaris returned credentials for the crafted table, the path restriction inside the configured bucket was effectively gone.

The practical effect is that temporary credentials for one crafted table can be broader than the table Polaris was asked to authorize, and can become effectively bucket-wide within the configured bucket.

The current GCS testing used a Polaris principal with broad catalog privileges for setup. A separate least-privilege Polaris RBAC variant has not yet been tested on GCS. However, the storage-credential broadening behavior itself has been confirmed on GCS.

Detalles técnicos trazas, registros y código del informe original

- list another table's object prefix;

- read another table's metadata control file (Iceberg metadata JSON);

- create and delete an object under another table's object prefix;

CVSS

Versión: 4.0
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Puntuación base: 9.4

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.72%
Percentil entre todas las CVEs puntuadas: 52
Fecha de la puntuación: 5/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement85 %
Impacto principalT1552.007 Container APIcredential access90 %
Impacto secundarioT1565.001 Stored Data Manipulationimpact70 %
Impacto secundarioT1578.003 Delete Cloud Instancedefense impairment75 %

Vulnerabilidad en Apache Polaris que permite a un atacante autenticado (PR:L) manipular identificadores de namespace/tabla para evadir restricciones CEL en credenciales GCS, obteniendo acceso a datos y control sobre múltiples tablas y prefijos de almacenamiento no autorizados.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

User Account Management Privileged Account Management Network Segmentation Vulnerability Scanning Threat Intelligence Program Restrict File and Directory Permissions

Tecnologías afectadas (1)

Apache — Polaris

CWE

CWE-20, CWE-917

Referencias

JSON original (NVD)

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      "value": "In plain terms, Apache Polaris is supposed to issue short-lived GCS credentials\nthat\nonly work for one table's files, but a crafted namespace or table name can\ncause those credentials to work across the configured bucket instead.\n\n\nApache Polaris builds Google Cloud Storage downscoped credentials by creating a\nCredential Access Boundary (CAB) with CEL conditions that are intended to\nrestrict access to the requested table's storage path.\n\n\n\nThe relevant CEL string is built from the bucket name and the table path.\nThat\ntable path is derived from namespace and table identifiers. In current code,\nthat path appears to be inserted into the CEL expression without escaping.\n\n\n\nAs a result, a namespace or table identifier containing a single quote and\nother URI-safe CEL fragments can break out of the intended quoted string and\nchange the meaning of the CEL condition.\n\n\n\nIn private testing against Polaris 1.4.0 on real Google Cloud Storage, it was confirmed that Polaris accepted a crafted identifier and returned delegated\nGCS\ncredentials whose CEL path restriction had effectively collapsed.\n\n\nThose delegated credentials could then:\n\n\n- list another table's object prefix;\n\n- read another table's metadata control file (Iceberg metadata JSON);\n\n- create and delete an object under another table's object prefix;\n\n- and also list, read, create, and delete objects under an unrelated\nexternal\nprefix in the same bucket that was not part of any table path.\n\n\n\nThat last point is important. The issue is not limited to \"another table\".\nIn\nthe confirmed setup, once Apache Polaris returned credentials for the crafted\ntable,\nthe path restriction inside the configured bucket was effectively gone.\n\nThe practical effect is that temporary credentials for one crafted table\ncan be\nbroader than the table Polaris was asked to authorize, and can become\neffectively bucket-wide within the configured bucket.\n\n\n\nThe current GCS testing used a Polaris principal with broad catalog\nprivileges for setup. A separate least-privilege Polaris RBAC variant\nhas not yet been tested on GCS. However, the storage-credential\nbroadening behavior itself has been confirmed on GCS."
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