# CVE-2026-7439: AgentFlow Local Web API Content-Type Validation Bypass

Status: published. Published: 2026-04-29. Updated: 2026-11-08.

AgentFlow's local web API accepts non-JSON content types on POST /api/runs and POST /api/runs/validate endpoints without enforcing application/json validation, allowing attackers to bypass trust-boundary enforcement on sensitive operations. Attackers can exploit this content-type validation weakness through browser-driven or local cross-origin requests to abuse the localhost API and enable attack chains against the local control plane.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/berabuddies/agentflow/pull/18
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/berabuddies/agentflow/commit/1667fa3

## Affected products and versions

- berabuddies / AgentFlow: ≥ 0; < 1667fa3 (affected, git). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 4.8 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 4.4 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.09% as of 2026-11-08; percentile 0.37%

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

- Weaknesses: CWE-346

## Exploit evidence

- exploit: https://github.com/berabuddies/agentflow/pull/18 (ADP: CISA-ADP)

## References

- https://github.com/berabuddies/agentflow/pull/18 (CNA: VulnCheck; issue-tracking, patch)

- https://github.com/berabuddies/agentflow/commit/1667fa3 (CNA: VulnCheck; patch)

- https://www.vulncheck.com/advisories/agentflow-local-web-api-content-type-validation-bypass (CNA: VulnCheck; third-party-advisory)

- https://github.com/berabuddies/agentflow/pull/18 (ADP: CISA-ADP; exploit)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-7439; retrieved 2026-11-08; source updated 2026-11-08

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-7439; retrieved 2026-11-08; source updated Not reported

Revision: 554c2d332d0022e4507980426cb81e46dc7a7befcbbe435dfbd2c68c7330ea2a

Canonical: https://y2.dev/cve/CVE-2026-7439

## 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.