CVE-2026-42810
CRITICALApache 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…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
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.
Affected Products
polarisapacheDetection & mitigation playbook
Vendor / applianceDetect
Inventory every apache polaris deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the apache polaris security patch or hotfix for CVE-2026-42810 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-42810 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-42810. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-42810 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-42810 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.