CVE-2026-42811: Apache Polaris Credential Bypass Exposes Cloud Storage
The National Vulnerability Database has disclosed CVE-2026-42811, a critical vulnerability in Apache Polaris. This flaw allows specially crafted namespace or table names to bypass intended access controls for Google Cloud Storage (GCS) credentials. Instead of restricting access to a single table’s files as designed, an attacker can exploit this to gain credentials that grant broad access across the entire configured bucket.
This bypass occurs because Polaris fails to properly escape table identifiers when constructing CEL (Common Expression Language) conditions for downscoped GCS credentials. A malicious identifier containing a single quote can effectively break out of the intended string, collapsing the path restriction. The National Vulnerability Database confirmed that crafted credentials could then list, read, create, or delete objects not only in other tables but also in unrelated prefixes within the same bucket, effectively negating the intended security boundary.
Defenders should immediately assess their use of Apache Polaris for GCS integrations. Given the CVSS score of 9.9, this vulnerability represents a critical risk. Prioritize patching or upgrading Polaris to a version that addresses this flaw. For affected systems, an immediate audit of GCS access logs is recommended to identify any anomalous activity, particularly involving unauthorized object manipulation or access to unexpected prefixes within buckets managed by Polaris.
What This Means For You
- If your organization uses Apache Polaris to manage Google Cloud Storage credentials, you must verify your Polaris version and apply necessary patches immediately. Audit your GCS buckets for any unauthorized access or modification attempts that could stem from a bypassed credential boundary, especially if you've seen unusual activity involving unrelated prefixes.
Related ATT&CK Techniques
🛡️ Detection Rules
3 rules · 6 SIEM formats3 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
CVE-2026-42811: Apache Polaris Crafted Namespace/Table Name for GCS Credential Bypass
title: CVE-2026-42811: Apache Polaris Crafted Namespace/Table Name for GCS Credential Bypass
id: scw-2026-05-04-ai-1
status: experimental
level: critical
description: |
This rule detects the specific exploit pattern for CVE-2026-42811 where a crafted namespace or table name containing a single quote and other CEL fragments is used to bypass GCS credential restrictions in Apache Polaris. This allows an attacker to gain broader access to cloud storage than intended.
author: SCW Feed Engine (AI-generated)
date: 2026-05-04
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-42811/
tags:
- attack.initial_access
- attack.t1190
logsource:
category: webserver
detection:
selection:
cs-uri|contains:
- "/api/v1/namespaces"
cs-uri-query|contains:
- "table_name=' OR '1'='1"
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-42811 | Vulnerability | CVE-2026-42811 |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 04, 2026 at 20:16 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
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