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Response snapshot Oct 27, 2026, 00:51 UTC

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VulnerabilityCVE-2026-42810

Apache Polaris accepts literal `*` characters in namespace and table names.

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.

Published Updated

At a glance

Exploited
Not known
Severity
9.4 Critical (CVSS 4.0)
Chance of exploitation
0.4% in the next 30 days
Sources
2 independent sources

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-42810 (opens a new tab)

What happened

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:

Continue reading

- 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.

Scores and how they were measured

CVSS base severity

9.4

Version 4.0As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.4%

Scored Percentile 36.5%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-42810 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    Vendor advisory (via NVD references) (opens a new tab)

    The vendor advisory referenced by the CVE record, for affected versions and fixes.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  5. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  6. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-42810, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 26). Apache Polaris accepts literal `*` characters in namespace and table names. (CVE-2026-42810). https://kevwire.com/record/CVE-2026-42810

MLA

"Apache Polaris accepts literal `*` characters in namespace and table names. (CVE-2026-42810)." KEVWire, 26 Oct. 2026, kevwire.com/record/CVE-2026-42810.

Chicago

KEVWire. "Apache Polaris accepts literal `*` characters in namespace and table names. (CVE-2026-42810)." Last modified October 26, 2026. https://kevwire.com/record/CVE-2026-42810.

Evidence summary (plain text)

Apache Polaris accepts literal `*` characters in namespace and table names. (May 4, 2026).
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.
CVSS 9.4 (version 4.0; evidence as of Oct 26, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-42810).
EPSS 0.4% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-42810&date=2026-10-26).
Sources:
NVD CVE-2026-42810: https://nvd.nist.gov/vuln/detail/CVE-2026-42810
Vendor advisory (via NVD references): https://lists.apache.org/thread/gg3qq9sqg4hdjmprqy46p40xmln61dm9
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T19:01:15.495Z&lastModEndDate=2026-10-26T20:30:55.133Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T18:27:03.991Z&lastModEndDate=2026-10-26T20:00:55.952Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T17:56:10.576Z&lastModEndDate=2026-10-26T19:25:57.867Z&resultsPerPage=500&startIndex=0
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-42810&date=2026-10-26
Record ID: CVE-2026-42810.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 26, 2026, 19:40 UTC. Ingestion is not an independent editorial investigation.

NVD status: Analyzed. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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