# CVE-2026-53639 — Sylius

> As of 2026-09-09, CVE-2026-53639 is a Medium-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in Sylius, CVSS v4.0 6.3, EPSS 0.5% (43.8th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-53639 as of 2026-09-09; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-09-09

## What is CVE-2026-53639?

Sylius is an Open Source eCommerce Framework on Symfony. Starting in version 2.0.0 and prior to version 2.0.18, 2.1.15, and 2.2.6, the `GET /api/v2/shop/payment-requests/{hash}` and `PUT /api/v2/shop/payment-requests/{hash}` endpoints look up the payment request solely by the hash from the URL. No ownership check is performed against the authenticated customer or the underlying order. An attacker who obtains a payment request hash can read the payment request and, through the `payment` IRI in the response, recover the underlying order's `tokenValue` (which itself grants access to the full order, items, addresses, customer email, totals); and/or update the payment request payload (e.g. `target_path`, `after_path`). These fields are used by the front-end controller to redirect the user after the payment, so an attacker can flip them to an attacker-controlled URL and intercept the buyer. The hash is a UUID, so it has to be obtained out-of-band (logs, shared links, referrer headers, a co-located client), but once it is known no other credential is required, neither authentication nor knowledge of the order token. The creation endpoint `POST /api/v2/shop/orders/{tokenValue}/payment-requests` shares the same flaw: it resolves the target order solely from the `tokenValue` in the URL without verifying that the caller owns the order. The issue is fixed in versions 2.0.18, 2.1.15, and 2.2.6. As a workaround, add a query extension that filters the `GET` operation; decorate the `PUT` state provider, guard the `POST` creation endpoint with a command-bus middleware, and wire the services.

The record classifies CVE-2026-53639 under weakness class [CWE-639](https://intel.threadlinqs.com/cwe/CWE-639). 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 27 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 6.3 — Medium (derived from score) (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **EPSS (FIRST):** 0.5% probability of exploitation in the next 30 days, higher than 43.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-08, last modified 2026-09-09

## Is CVE-2026-53639 being exploited?

It currently carries a trending score of 41 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **Sylius**: Sylius

## How to fix CVE-2026-53639

No vendor patch reference has been recorded for CVE-2026-53639 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-53639

No threat campaign in the Threadlinqs corpus currently references CVE-2026-53639, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on 2026-09-09.

**Vendor advisory and patch**

- [github.com](https://github.com/Sylius/Sylius/security/advisories/GHSA-mr9r-h354-966r)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-53639
Full detection coverage and IOCs for threats exploiting CVE-2026-53639 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp