CVE-2026-42811
Apache Polaris: could broaden vended GCS credentials through unescaped identifier content in access-boundary CEL conditions
Description
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. 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: - 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; - 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.
INFO
Published Date :
May 4, 2026, 5:16 p.m.
Last Modified :
Oct. 26, 2026, 7:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | f0158376-9dc2-43b6-827c-5f631a4d8d09 | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | f0158376-9dc2-43b6-827c-5f631a4d8d09 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update Apache Polaris to a patched version.
- Validate GCS credential access restrictions.
- Review CEL expression escaping logic.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42811.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread/hovn5hmkj9wj7v9cd8sn67svg03klgvg | Mailing List Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2026/05/02/12 | Mailing List Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42811 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42811
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42811 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42811 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Oct. 26, 2026
Action Type Old Value New Value Added Translation Title: Apache Polaris de Apache Software Foundation, Description: En términos sencillos, se supone que Apache Polaris emite credenciales de GCS de corta duración que solo funcionan para los archivos de una tabla, pero un nombre de espacio de nombres o de tabla manipulado puede hacer que esas credenciales funcionen en todo el bucket configurado en su lugar. Apache Polaris construye credenciales de Google Cloud Storage de alcance reducido creando un Límite de Acceso a Credenciales (CAB) con condiciones CEL que están destinadas a restringir el acceso a la ruta de almacenamiento de la tabla solicitada. La cadena CEL relevante se construye a partir del nombre del bucket y la ruta de la tabla. Esa ruta de tabla se deriva de identificadores de espacio de nombres y de tabla. En el código actual, esa ruta parece insertarse en la expresión CEL sin escape. Como resultado, un identificador de espacio de nombres o de tabla que contiene una comilla simple y otros fragmentos CEL seguros para URI puede salirse de la cadena entre comillas prevista y cambiar el significado de la condición CEL. En pruebas privadas contra Polaris 1.4.0 en Google Cloud Storage real, se confirmó que Polaris aceptó un identificador manipulado y devolvió credenciales de GCS delegadas cuya restricción de ruta CEL se había colapsado efectivamente. Esas credenciales delegadas podrían entonces: - listar el prefijo de objeto de otra tabla; - leer el archivo de control de metadatos de otra tabla (JSON de metadatos de Iceberg); - crear y eliminar un objeto bajo el prefijo de objeto de otra tabla; - y también listar, leer, crear y eliminar objetos bajo un prefijo externo no relacionado en el mismo bucket que no formaba parte de ninguna ruta de tabla. Ese último punto es importante. El problema no se limita a ’otra tabla’. En la configuración confirmada, una vez que Apache Polaris devolvió credenciales para la tabla manipulada, la restricción de ruta dentro del bucket configurado había desaparecido efectivamente. El efecto práctico es que las credenciales temporales para una tabla manipulada pueden ser más amplias que la tabla que se le pidió a Polaris que autorizara, y pueden volverse efectivamente a nivel de bucket dentro del bucket configurado. Las pruebas actuales de GCS utilizaron un principal de Polaris con amplios privilegios de catálogo para la configuración. Una variante separada de RBAC de Polaris de mínimo privilegio aún no se ha probado en GCS. Sin embargo, el comportamiento de ampliación de las credenciales de almacenamiento en sí mismo ha sido confirmado en GCS. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Apache Software Foundation', 'product': 'Apache Polaris', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.4.1', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-42811', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-05-04T19:48:24.896527Z'} -
Initial Analysis by [email protected]
May. 12, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:apache:polaris:*:*:*:*:*:*:*:* versions up to (excluding) 1.4.1 Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/05/02/12 Types: Mailing List, Third Party Advisory Added Reference Type Apache Software Foundation: https://lists.apache.org/thread/hovn5hmkj9wj7v9cd8sn67svg03klgvg Types: Mailing List, Vendor Advisory -
New CVE Received by [email protected]
May. 04, 2026
Action Type Old Value New Value Added Description 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. 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: - 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; - 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Added CWE CWE-20 Added CWE CWE-917 Added Reference https://lists.apache.org/thread/hovn5hmkj9wj7v9cd8sn67svg03klgvg -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
May. 04, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/05/02/12