Apache Polaris: Improper Input Validation (CVE-2026-42810)
Published Last modified Sources: CVE.org, OSV, EUVD
What is affected, what to do
Update Apache Polaris to version 1.4.1.
- Affected
- Apache Polaris
lt *..1.4.1
- Apache Polaris
- Fixed in
- Apache Polaris
1.4.1
- Apache Polaris
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Metrics
9.9
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
9.9
CVSS v3
Severity Critical on the scale from 0 to 10.
Source: CVE.org, OSV, EUVD
0.4 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 36.7
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 77.26 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 9.9 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 9.9
CVSS v4
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 9.4
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 0.4 %
- Low — model estimates < 1% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 36.7
- High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
- CISA assessment (SSVC)
- Exploitation: none known · not automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 4 May 2026
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-20, CWE-116
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
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.
Source: NVD (NIST), OSV (Open Source Vulnerabilities), cvelistv5, CVE.org (MITRE), ENISA EUVD
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Apache Software Foundation | Apache Polaris |
|
|
| apache | polaris |
|
|
| maven | org.apache.polaris:polaris-core |
|
|
Vendors and products
Weakness classes (CWE)
CWE-20Improper Input Validation
Class
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
Entry at MITRE CWE-20CWE-116Improper Encoding or Escaping of Output
Class
The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
Entry at MITRE CWE-116
References & sources
- NVD (NIST)vuln/detail/CVE-2026-42810advisory
- github.comapache/polaris/commit/da54eb15c2c42c59afedefacbe7a528856b07c0aweb
- github.comapache/polarispackage
- lists.apache.orgthread/gg3qq9sqg4hdjmprqy46p40xmln61dm9web, Vendor advisory, Mailing list, Vendor advisory
- openwall.comlists/oss-security/2026/05/02/11web, Mailing list, Third-party advisory
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
One NVD translation into another language is hidden.
Linked advisories
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-42810"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-42810.svg?lang=en" alt="CVE-2026-42810 – NEOSEC Intel" height="20"></a>