# CVE-2026-42811: Apache Polaris has an Improper Input Validation issue > Attackers can inject CEL code via crafted identifiers to broaden GCS credentials, allowing unauthorized read and write access to other tables or bucket contents. - **Severity:** Critical 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`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 May 2026 - **Updated:** 4 May 2026 - **Also known as:** GHSA-fc3h-c6h7-r83j ## What is CVE-2026-42811? CVE-2026-42811 is a critical code injection vulnerability in Apache Polaris, published on 4 May 2026. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description In plain terms, Apache Polaris is supposed to issue short-lived GCS credentials that only work for one table's files, but a crafted namespace or table name can cause those credentials to work across the configured bucket instead. Apache Polaris builds Google Cloud Storage downscoped credentials by creating a Credential Access Boundary (CAB) with CEL conditions that are intended to restrict access to the requested table's storage path. The relevant CEL string is built from the bucket name and the table path. That table path is derived from namespace and table identifiers. In current code, that path appears to be inserted into the CEL expression without escaping. As a result, a namespace or table identifier containing a single quote and other URI-safe CEL fragments can break out of the intended quoted string and change the meaning of the CEL condition. In private testing against Polaris 1.4.0 on real Google Cloud Storage, it was confirmed that Polaris accepted a crafted identifier and returned delegated GCS credentials whose CEL path restriction had effectively collapsed. Those delegated credentials could then: - list another table's object prefix; - read another table's metadata control file (Iceberg metadata JSON); - create and delete an object under another table's object prefix; - and also list, read, create, and delete objects under an unrelated external prefix in the same bucket that was not part of any table path. That last point is important. The issue is not limited to "another table". In the confirmed setup, once Apache Polaris returned credentials for the crafted table, the path restriction inside the configured bucket was effectively gone. The practical effect is that temporary credentials for one crafted table can be broader than the table Polaris was asked to authorize, and can become effectively bucket-wide within the configured bucket. The current GCS testing used a Polaris principal with broad catalog privileges for setup. A separate least-privilege Polaris RBAC variant has not yet been tested on GCS. However, the storage-credential broadening behavior itself has been confirmed on GCS. Weakness: CWE-917 (Improper Neutralization of Special Elements used in an Expression Language Statement), CWE-20 (Improper Input Validation) ## Which versions are affected by CVE-2026-42811? 2 open source packages ship an affected version, including org.apache.polaris:polaris-core. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `org.apache.polaris:polaris-core` | Maven | All versions | 1.4.1 | | `org.apache.polaris:polaris-core` | Maven | All versions | 1.4.1 | Products: Apache Polaris. ## How do I fix CVE-2026-42811? Upgrade org.apache.polaris:polaris-core to 1.4.1 or later. ## Is CVE-2026-42811 being exploited? There is no known exploitation of CVE-2026-42811 in the wild and no public exploit code. ## Other vulnerabilities in Apache Polaris - [CVE-2026-42809](https://insights.sbomify.com/CVE-2026-42809/): Apache Polaris: staged table creation could vend storage credentials for unvalidated locations (critical 9.4) - [CVE-2026-42810](https://insights.sbomify.com/CVE-2026-42810/): Apache Polaris: could broaden vended S3 credentials through wildcard-bearing namespace or table names (critical 9.4) - [CVE-2026-42812](https://insights.sbomify.com/CVE-2026-42812/): Apache Polaris: No protection on `write.metadata.path` (critical 9.4) - [CVE-2026-64640](https://insights.sbomify.com/CVE-2026-64640/): Apache Polaris: register endpoint reads attacker-controlled storage location before allowed-locations validation (medium 5.3) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-42811 and fix it if it is affected. What it is: CVE-2026-42811 is a critical code injection vulnerability in Apache Polaris, published on 4 May 2026. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-42811 in the wild and no public exploit code. Affected packages and fixed versions: - org.apache.polaris:polaris-core (Maven): affected all versions; fixed in 1.4.1 - org.apache.polaris:polaris-core (Maven): affected all versions; fixed in 1.4.1 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-42811/ (Markdown: https://insights.sbomify.com/CVE-2026-42811/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42811 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42811 - OSV: https://osv.dev/vulnerability/CVE-2026-42811 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-42811/ Summaries are generated and may contain mistakes; the official description above is the record.