Monitor vulnerabilities like this one.
Sign up free to get alerted when software you use is affected.
9.4
CVE-2026-42810: Apache Polaris allows unauthorized access to S3 data
CVE-2026-42810
GHSA-vxgg-mqx2-3w59
Summary
Apache Polaris doesn't properly handle certain characters in table names, which can allow an attacker to access data from other tables on Amazon S3. This is a security risk because an attacker could potentially read, list, or delete data from another table. To mitigate this issue, consider avoiding the use of '*' in table names or updating to a newer version of Apache Polaris that fixes this problem.
What to do
- Update org.apache.polaris:polaris-core to version 1.4.1.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| maven | – | org.apache.polaris:polaris-core |
< 1.4.1 Fix: upgrade to 1.4.1
|
Original title
Apache Polaris has an Improper Input Validation Issue
Original description
Apache Polaris accepts literal `*` characters in namespace and table names. When it later builds temporary S3 access policies for delegated table access, those same characters appear to be reused unescaped in S3 IAM resource patterns and `s3:prefix` conditions.
In S3 IAM policy matching, `*` is treated as a wildcard rather than as ordinary text. That means temporary credentials issued for one crafted table can match the storage path of a different table.
In private testing against Polaris 1.4.0 using Polaris' AWS S3 temporary-credential path on both MinIO and real AWS S3, credentials returned for crafted tables such as `f*.t1`, `f*.*`, `*.*`, and `foo.*` could reach other tables' S3 locations.
The confirmed behavior includes:
- reading another table's metadata control file ([Iceberg metadata JSON]);
- listing another table's exact S3 table prefix ([table prefix]);
- and, when write delegation was returned for the crafted table, creating and deleting an object under another table's exact S3 table prefix.
A control case using ordinary different names did not allow the same cross-table access.
A least-privilege AWS S3 variant was also confirmed in which the attacker principal had no Polaris permissions on the victim table and only the minimal permissions required to create and use a crafted wildcard table (namespace-scoped `TABLE_CREATE` and `TABLE_WRITE_DATA` on `*`). In that setup, direct Polaris access to `foo.t1` remained forbidden, but the attacker could still create and load `*.*`, receive delegated S3 credentials, and use those credentials to list, read, create, and delete objects under `foo.t1`.
In Iceberg, the metadata JSON file is a control file: it tells readers which data files belong to the table, which snapshots exist, and which table version to read. So unauthorized access to it is already a meaningful confidentiality problem. The confirmed write-capable variant means the issue is not limited to disclosure.
In S3 IAM policy matching, `*` is treated as a wildcard rather than as ordinary text. That means temporary credentials issued for one crafted table can match the storage path of a different table.
In private testing against Polaris 1.4.0 using Polaris' AWS S3 temporary-credential path on both MinIO and real AWS S3, credentials returned for crafted tables such as `f*.t1`, `f*.*`, `*.*`, and `foo.*` could reach other tables' S3 locations.
The confirmed behavior includes:
- reading another table's metadata control file ([Iceberg metadata JSON]);
- listing another table's exact S3 table prefix ([table prefix]);
- and, when write delegation was returned for the crafted table, creating and deleting an object under another table's exact S3 table prefix.
A control case using ordinary different names did not allow the same cross-table access.
A least-privilege AWS S3 variant was also confirmed in which the attacker principal had no Polaris permissions on the victim table and only the minimal permissions required to create and use a crafted wildcard table (namespace-scoped `TABLE_CREATE` and `TABLE_WRITE_DATA` on `*`). In that setup, direct Polaris access to `foo.t1` remained forbidden, but the attacker could still create and load `*.*`, receive delegated S3 credentials, and use those credentials to list, read, create, and delete objects under `foo.t1`.
In Iceberg, the metadata JSON file is a control file: it tells readers which data files belong to the table, which snapshots exist, and which table version to read. So unauthorized access to it is already a meaningful confidentiality problem. The confirmed write-capable variant means the issue is not limited to disclosure.
nvd CVSS3.1
9.9
nvd CVSS4.0
9.4
Vulnerability type
CWE-20
Improper Input Validation
CWE-116
- https://lists.apache.org/thread/gg3qq9sqg4hdjmprqy46p40xmln61dm9
- https://nvd.nist.gov/vuln/detail/CVE-2026-42810
- http://www.openwall.com/lists/oss-security/2026/05/02/11
- https://github.com/apache/polaris/commit/da54eb15c2c42c59afedefacbe7a528856b07c0...
- https://github.com/advisories/GHSA-vxgg-mqx2-3w59
Published: 4 May 2026 · Updated: 30 May 2026 · First seen: 4 May 2026