CVE-2026-55098

MEDIUM CVSS 3.1: 6.5 EPSS 0.32%
Updated Oct 30, 2026
Arc
Parameter Value
CVSS 6.5 (MEDIUM)
Type CWE-863 (Incorrect Authorization), CWE-200 (Information Exposure)
Vendor Arc
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
None
No data modification
Availability
None
No disruption

CVSS Vector v3.1