CVE-2026-42810

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-04 17:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-26 19:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 9.4 CRITICAL (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-05-04 17:16 UTC

Last modified

2026-10-26 19:10 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-20 · Improper input validation

Record status

Analyzed

Affected

• Apache Polaris < 1.4.1

Attack profile CVSS 4.0 · 9.4

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

None

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

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