# CVE-2026-118377: mews/pos through 2.0.0 Missing Hash Verification in 3D Pay and 3D Host Callbacks

Status: published. Published: 2026-10-28. Updated: 2026-11-04.

mews/pos through 2.0.0 contains an insufficient verification of data authenticity vulnerability that allows unauthenticated attackers to forge payment results by submitting unverified callbacks. GarantiPos, PayForPos and InterPos 3D Pay and 3D Host handlers skip check3DHash(), letting attackers post tampered status, amount or order ID fields to complete orders without paying.

## 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/mewebstudio/pos/pull/305
- 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/mewebstudio/pos/commit/7c59d42bc49483c7c54999d757cb67055d9f732a

## Affected products and versions

- mewebstudio / pos (mews/pos): ≥ 0; ≤ 2.0.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.18% as of 2026-11-04; percentile 7.64%

- SSVC: exploitation none; automatable yes; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-345

## Exploit evidence

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

## References

- https://github.com/mewebstudio/pos/pull/305 (CNA: VulnCheck; patch, issue-tracking)

- https://github.com/mewebstudio/pos/commit/7c59d42bc49483c7c54999d757cb67055d9f732a (CNA: VulnCheck; patch)

- https://github.com/mewebstudio/pos/issues/306 (CNA: VulnCheck; issue-tracking)

- https://github.com/mewebstudio/pos/blob/50ed2bfe4f8980b8b0c47996de571943fa58d7ad/src/Gateway/PayForPos.php#L135-L150 (CNA: VulnCheck; technical-description)

- https://github.com/mewebstudio/pos/blob/50ed2bfe4f8980b8b0c47996de571943fa58d7ad/src/Gateway/InterPos.php#L134-L149 (CNA: VulnCheck; technical-description)

- https://github.com/mewebstudio/pos (CNA: VulnCheck; product)

- https://www.vulncheck.com/advisories/mews-pos-through-2.0.0-missing-hash-verification-in-3d-pay-and-3d-host-callbacks (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-118377; retrieved 2026-11-04; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-118377; retrieved 2026-11-04; source updated Not reported

Revision: e8789b5fd3ae3ae3f42845a22be9b35a70e5301400a99399a32d166c194a4463

Canonical: https://y2.dev/cve/CVE-2026-118377

## 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.