Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.69% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-42810High confidence
Apache Polaris: could broaden vended S3 credentials through wildcard-bearing namespace or table names
Apache Software Foundation · Apache Polaris
9.4CriticalCVSS 4.0
Within 7 days
Fix not verifiedCritical technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Apache Software Foundation Apache Polaris and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Open-source package ranges1 source-attributed range
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| mavenorg.apache.polaris:polaris-core | < 1.4.1 | 1.4.1 | GitHub advisory ↗github reviewed aggregator · 8 May 2026 |
Critical technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
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.
What
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.
Why
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.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
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.
Why
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.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Improper Encoding or Escaping of Output → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-116 ↗
CWE-116: Improper Encoding or Escaping of Output. 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.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SIHighSubsequent-system integrity: A successful attack can cause a major loss.SAHighSubsequent-system availability: A successful attack can cause a major loss.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix not verified
- Affected
- Apache Polaris: < 1.4.1
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 4 May 2026 · Last source change 4 May 2026, 18:33 UTC · CWE-116 · Improper Encoding or Escaping of Output
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-27035
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.