# CVE-2026-126403: Coder 2.38.0 before 2.38.4 Authorization Bypass via External Agent Credentials Endpoint

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

Coder 2.26.0 before 2.29.24, 2.30.0 before 2.34.16, 2.35.0 before 2.36.11, 2.37.0 before 2.37.8, and 2.38.0 before 2.38.4 contains an improper authorization flaw in the external agent credentials endpoint, which returns the workspace agent token to users with only workspace read access rather than ssh permission. Authenticated users with roles such as Template Admin or Organization Admin can use the token to read the owner's private Git SSH key and Git provider OAuth tokens, and impersonate the agent to receive the owner's sessions.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- coder / coder (github.com/coder/coder/v2): ≥ 2.38.0; < 2.38.4 (affected, semver); 2.38.4 (unaffected, semver). Source: CNA: VulnCheck
- coder / coder (github.com/coder/coder/v2): ≥ 2.37.0; < 2.37.8 (affected, semver); 2.37.8 (unaffected, semver). Source: CNA: VulnCheck
- coder / coder (github.com/coder/coder/v2): ≥ 2.36.0; < 2.36.11 (affected, semver); 2.36.11 (unaffected, semver). Source: CNA: VulnCheck
- coder / coder (github.com/coder/coder/v2): ≥ 2.30.0; < 2.34.16 (affected, semver); 2.34.16 (unaffected, semver). Source: CNA: VulnCheck
- coder / coder (github.com/coder/coder/v2): ≥ 2.26.0; < 2.29.24 (affected, semver); 2.29.24 (unaffected, semver). Source: CNA: VulnCheck
- coder / coder (github.com/coder/coder/v2): ≥ 2.35.0; < 2.36.0 (affected, semver); 2.36.0 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.5 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

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

- CVSS 4.0: 8.5 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/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: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.40% as of 2026-11-13; percentile 34.98%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-863

## Exploit evidence

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

## References

- https://github.com/coder/coder/security/advisories/GHSA-9frj-7f83-x984 (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/coder-2.38.0-before-2.38.4-authorization-bypass-via-external-agent-credentials-endpoint (CNA: VulnCheck; third-party-advisory)

- https://github.com/coder/coder/security/advisories/GHSA-9frj-7f83-x984 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/coder-2.38.0-before-2.38.4-authorization-bypass-via-external-agent-credentials-endpoint (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-126403; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-126403; retrieved 2026-11-13; source updated 2026-11-13

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-126403; retrieved 2026-11-13; source updated Not reported

Revision: a0ad712d6db60a3cc4648a3e682fd3af119fc07c6e7a85bd315ba23de66eaa05

Canonical: https://y2.dev/cve/CVE-2026-126403

## 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.