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Fencer Vulns
critical 9.9

CVE-2026-42810 json

Apache Polaris: could broaden vended S3 credentials through wildcard-bearing namespace or table names

published 2026-05-04 6 mo ago modified 2026-10-26 13 d ago also GHSA-vxgg-mqx2-3w59 , EUVD-2026-27035

cvss
9.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.apache.polaris:polaris-core 1.4.1
  • Apache Software Foundation Apache Polaris 1.4.1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
6 mo ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 9.4 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
CNA 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CNA 4.0 9.4 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
GitHub 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
maven org.apache.polaris:polaris-core
<1.4.1
1.4.1

Affected products

  • Apache Software Foundation Apache Polaris

Classification

Weakness
  • CWE-116 Improper Encoding or Escaping of Output
  • CWE-20 Improper Input Validation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.