Vulnerability · Published Oct 30, 2026 · Assigned by GitHub_M
CVE-2026-55098Arc: DuckDB I/O aliases bypass database RBAC after CVE-2026-47735
Medium 6.5
In plain English
A medium-severity information exposure in arc from Basekick-Labs. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Arc is an open, SQL-native time-series database for telemetry. Prior to the repository-verified 26.06.2 repair, the remediation of `CVE-2026-47735` leaves a cross-database authorization bypass through DuckDB table-valued I/O functions. In `internal/database/sandbox.go`, `allowed_directories` uses `cfg.LocalStorageRoot`, configured by `storage.local_path`, while `enable_external_access=false` blocks access outside that entire multi-tenant root. `GetStoragePath` in `internal/storage/util.go` stores all databases beneath it. In `internal/api/query.go`, `extractTableReferences` skips names followed by an opening parenthesis and `checkQueryPermissions` allows queries with no extracted table references, including tokens with `permissions: []`. The `userSQLReadParquetPattern` denylist catches literal `read_parquet(` and the earlier protection also blocks `arc_partition_agg(`, but misses the `parquet_scan` alias and `glob`, `parquet_metadata`, `parquet_schema`, `read_blob`, `read_csv_auto`, `read_json` and `read_text`. A request to `POST /api/v1/query` using these unblocked functions passes `ValidateSQLRequest` and `convertSQLToStoragePaths` without tenant authorization, allowing reads and enumeration of other databases' time-series data, schema and per-column value-range statistics within the allowlisted root. The sandbox still blocks out-of-root OS files and HTTP SSRF, and the sibling SQLite token database outside the root is not exposed by this mechanism. The earlier 26.06.1 remediation does not comprehensively deny these I/O functions. Repository tag 26.06.2 contains the I/O-function repair and supplies the provisional remediation boundary; conflicting advisory affected-version statements require curator adjudication.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/basekick-labs/arc | 0.0.0-20260610131716-5dc8f53b70a3 | GHSA-93cm-2v4m-c56c |
| Go | github.com/basekick-labs/arc | 0.0.0-20260610131716-5dc8f53b70a3 | GO-2026-6913 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Basekick-Labs | arc | < 26.06.2 |
Weakness: CWE-200, CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
References
- https://github.com/Basekick-Labs/arc/security/advisories/GHSA-93cm-2v4m-c56c x_refsource_CONFIRM
- https://github.com/Basekick-Labs/arc/pull/495 x_refsource_MISC
- https://github.com/Basekick-Labs/arc/commit/5dc8f53b70a3871b16b0cebf328f07c578af7a45 x_refsource_MISC
- https://github.com/Basekick-Labs/arc/tree/v26.06.2 x_refsource_MISC