# CVE-2026-55098: Arc: DuckDB I/O aliases bypass database RBAC after CVE-2026-47735

Status: published. Published: 2026-10-30. Updated: 2026-11-02.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Basekick-Labs / arc: < 26.06.2 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.32% as of 2026-11-02; percentile 24.92%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-200, CWE-863

## Exploit evidence

- exploit: https://github.com/Basekick-Labs/arc/security/advisories/GHSA-93cm-2v4m-c56c (ADP: CISA-ADP)

## References

- https://github.com/Basekick-Labs/arc/security/advisories/GHSA-93cm-2v4m-c56c (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/Basekick-Labs/arc/pull/495 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/Basekick-Labs/arc/commit/5dc8f53b70a3871b16b0cebf328f07c578af7a45 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/Basekick-Labs/arc/tree/v26.06.2 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/Basekick-Labs/arc/security/advisories/GHSA-93cm-2v4m-c56c (ADP: CISA-ADP; exploit)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-55098; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-55098; retrieved 2026-11-02; source updated Not reported

Revision: 210fec0df7741cc70ae39f22d61e7f7f6970c95d5f4924f8fb320d0937eecf81

Canonical: https://y2.dev/cve/CVE-2026-55098

## Agent and API access

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- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

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