# CVE-2026-126276: NocoDB before 2026.08.1 Client Authentication Bypass via OAuth Token Exchange

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

NocoDB before 2026.08.1 contains an authentication bypass vulnerability in oauth-token.service.ts that treats PKCE as a substitute for confidential client authentication, skipping client secret verification when omitted. Attackers holding a captured authorization code and PKCE verifier can mint access tokens and 60-day refresh tokens for a confidential client without knowing its secret.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- nocodb / nocodb: ≥ 0; < 2026.08.1 (affected, custom); 2026.08.1 (unaffected, custom). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.2 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 6.3 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N; source: CNA: VulnCheck

- CVSS 4.0: 8.2 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 6.3 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-287

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/nocodb/nocodb/security/advisories/GHSA-4cx5-q9xx-5pgj (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/nocodb-before-2026.08.1-client-authentication-bypass-via-oauth-token-exchange (CNA: VulnCheck; third-party-advisory)

- https://github.com/nocodb/nocodb/security/advisories/GHSA-4cx5-q9xx-5pgj (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/nocodb-before-2026.08.1-client-authentication-bypass-via-oauth-token-exchange (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-126276; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-126276; retrieved 2026-11-13; source updated 2026-11-13

Revision: 113e6d2d2919e7bc39463d01e5d679b5329927c20601bd23d4bdaeaf73c0424a

Canonical: https://y2.dev/cve/CVE-2026-126276

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, 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.

Collected public records only. Check source status for coverage and freshness.