{"id":"CVE-2026-33035","aliases":["EUVD-2026-13561","GHSA-wfq5-qgqp-hvhv"],"status":"published","title":"Unauthenticated Reflected XSS via innerHTML in AVideo","description":"WWBN AVideo is an open source video platform. In versions 25.0 and below, there is a reflected XSS vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in a victim's browser. User input from a URL parameter flows through PHP's json_encode() into a JavaScript function that renders it via innerHTML, bypassing encoding and achieving full script execution. The vulnerability is caused by two issues working together: unescaped user input passed to JavaScript (videoNotFound.php), and innerHTML rendering HTML tags as executable DOM (script.js).  The attack can be escalated to steal session cookies, take over accounts, phish credentials via injected login forms, spread self-propagating payloads, and compromise admin accounts — all by exploiting the lack of proper input sanitization and cookie security (e.g., missing HttpOnly flag on PHPSESSID). The issue has been fixed in version 26.0.","severity":{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0033,"percentile":0.26471,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-03-17T20:05:23Z","modified":"2026-10-28T02:31:14Z","affected":[{"source":"ghsa","ecosystem":"Packagist","package":"wwbn/avideo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"25.0"}]}]},{"source":"osv","ecosystem":"Packagist","package":"wwbn/avideo","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"25.0"}]}],"versions":["10.4","10.8","11","11.1","11.1.1","11.5","11.6","12.4","14.3","14.3.1","14.4","18.0","21.0","22.0","24.0","25.0"]}],"products":[{"vendor":"wwbn","product":"avideo"}],"references":[{"url":"https://github.com/WWBN/AVideo/security/advisories/GHSA-wfq5-qgqp-hvhv","tags":["x_refsource_CONFIRM","Exploit","Vendor Advisory","advisory","web"]},{"url":"https://github.com/WWBN/AVideo/commit/cca6196f4072cb9acc39b1030fb8fb1702b4f69b","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33035","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-wfq5-qgqp-hvhv"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33035.json","tags":["advisory"]},{"url":"https://github.com/WWBN/AVideo","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-33035","title":"Unauthenticated Reflected XSS via innerHTML in AVideo","description":"WWBN AVideo is an open source video platform. In versions 25.0 and below, there is a reflected XSS vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in a victim's browser. User input from a URL parameter flows through PHP's json_encode() into a JavaScript function that renders it via innerHTML, bypassing encoding and achieving full script execution. The vulnerability is caused by two issues working together: unescaped user input passed to JavaScript (videoNotFound.php), and innerHTML rendering HTML tags as executable DOM (script.js).  The attack can be escalated to steal session cookies, take over accounts, phish credentials via injected login forms, spread self-propagating payloads, and compromise admin accounts — all by exploiting the lack of proper input sanitization and cookie security (e.g., missing HttpOnly flag on PHPSESSID). The issue has been fixed in version 26.0.","status":"published","published":"2026-03-20T05:08:31.54Z","modified":"2026-03-20T15:40:13.134Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:08.009733Z"}],"euvd":[{"id":"EUVD-2026-13561","description":"WWBN AVideo is an open source video platform. In versions 25.0 and below, there is a reflected XSS vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in a victim's browser. User input from a URL parameter flows through PHP's json_encode() into a JavaScript function that renders it via innerHTML, bypassing encoding and achieving full script execution. The vulnerability is caused by two issues working together: unescaped user input passed to JavaScript (videoNotFound.php), and innerHTML rendering HTML tags as executable DOM (script.js).  The attack can be escalated to steal session cookies, take over accounts, phish credentials via injected login forms, spread self-propagating payloads, and compromise admin accounts — all by exploiting the lack of proper input sanitization and cookie security (e.g., missing HttpOnly flag on PHPSESSID). The issue has been fixed in version 26.0.","status":"published","published":"2026-03-20T05:08:31Z","modified":"2026-03-20T15:40:13Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium"}],"updated_at":"2026-11-02T19:25:32.430758Z"}],"ghsa":[{"id":"GHSA-wfq5-qgqp-hvhv","title":"Unauthenticated Reflected XSS via innerHTML in AVideo","description":"## Summary\n\nAVideo contains a reflected XSS vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in a victim's browser. User input from a URL parameter flows through PHP's `json_encode()` into a JavaScript function that renders it via `innerHTML`, bypassing encoding and achieving full script execution.\n\n\n## Root Cause\nThe vulnerability is caused by two issues working together:\n\n### 1. Source: Unescaped user input passed to JavaScript (videoNotFound.php)\n\n**File:** `view/videoNotFound.php` line 49\n\n```php\nif (!empty($_REQUEST['404ErrorMsg'])) {\n    echo 'avideoAlertInfo(' . json_encode($_REQUEST['404ErrorMsg']) . ');';\n}\n```\n\nPHP's `json_encode()` with default flags only escapes quotes (`\"` → `\\\"`) and backslashes. It does **NOT** escape HTML special characters (`\u003c`, `\u003e`, `/`). The resulting string contains raw HTML tags that are passed directly to JavaScript.\n\n### 2. Sink: innerHTML renders HTML tags as executable DOM (script.js)\n\n**File:** `view/js/script.js`\n\n```javascript\nfunction avideoAlertInfo(msg) {            // line ~1891\n    avideoAlert(\"\", msg, 'info');           // calls ↓\n}\n\nfunction avideoAlert(title, msg, type) {   // line ~1270\n    avideoAlertHTMLText(title, msg, type);  // calls ↓\n}\n\nfunction avideoAlertHTMLText(title, msg, type) {  // line ~1451\n    var span = document.createElement(\"span\");\n    span.innerHTML = msg;                  // line 1464 — XSS SINK\n    swal({ content: span });\n}\n```\n\n`innerHTML` parses the string as HTML. Any `\u003cimg\u003e`, `\u003csvg\u003e`, or other HTML tags with event handlers are instantiated as real DOM elements, triggering JavaScript execution.\n\n### Data Flow\n\n```\nURL parameter (?404ErrorMsg=PAYLOAD)\n    → $_REQUEST['404ErrorMsg']\n    → json_encode()          ← does NOT escape \u003c \u003e /\n    → avideoAlertInfo()\n    → avideoAlert()\n    → avideoAlertHTMLText()\n    → span.innerHTML = msg   ← renders HTML tags, executes JS\n```\n\n---\n\n## Proof of Concept\n```\nhttps://localhost/view/videoNotFound.php?404ErrorMsg=\u003cimg src=x onerror=alert(document.domain)\u003e\n```\n\u003cimg width=\"1918\" height=\"1035\" alt=\"image\" src=\"https://github.com/user-attachments/assets/20077ce2-5b49-4bd3-a7df-ab48be786cc1\" /\u003e\n\nThe page renders:\n```javascript\navideoAlertInfo(\"\u003cimg src=x onerror=alert(document.domain)\u003e\");\n```\n\nWhich flows to `span.innerHTML = \"\u003cimg src=x onerror=alert(document.domain)\u003e\"`. The browser creates an `\u003cimg\u003e` element, `src=x` fails to load, `onerror` fires `alert(document.domain)`.\n\n## Affected Code\n\n| File | Line | Issue |\n|------|------|-------|\n| `view/videoNotFound.php` | 49 | `json_encode()` does not escape `\u003c` `\u003e` for HTML context |\n| `view/js/script.js` | 1464 | `span.innerHTML = msg` renders user input as HTML |\n| `view/js/script.js` | 1282 | `span.innerHTML = msg` in `avideoAlertWithCookie()` |\n| `view/js/script.js` | 1335 | `span.innerHTML = __(msg,true)` in `avideoConfirm()` |\n| `view/js/script.js` | 1358 | `span.innerHTML = msg` in `avideoAlertOnceForceConfirm()` |\n\nThe `innerHTML` sink exists in 4 functions. Any future code that passes user input to `avideoAlertInfo()`, `avideoAlertWarning()`, `avideoAlertDanger()`, or `avideoAlertSuccess()` will create additional XSS vectors.\n\n\n## Remediation\n\n### Fix 1: Escape HTML in PHP (source fix)\n\n```php\n// view/videoNotFound.php line 49\n// BEFORE (vulnerable):\necho 'avideoAlertInfo(' . json_encode($_REQUEST['404ErrorMsg']) . ');';\n\n// AFTER (fixed):\necho 'avideoAlertInfo(' . json_encode($_REQUEST['404ErrorMsg'], JSON_HEX_TAG | JSON_HEX_AMP) . ');';\n```\n\n`JSON_HEX_TAG` converts `\u003c` → `\\u003C` and `\u003e` → `\\u003E`, preventing HTML injection.\n\n### Fix 2: Use textContent instead of innerHTML (sink fix, recommended)\n\n```javascript\n// view/js/script.js - all alert functions\n// BEFORE (vulnerable):\nspan.innerHTML = msg;\n\n// AFTER (fixed):\nspan.textContent = msg;\n```\n\n`textContent` treats the string as plain text — HTML tags are displayed literally, never parsed or executed.\n\n### Fix 3: Add Content-Security-Policy header (defense in depth)\n\n```\nContent-Security-Policy: default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'\n```\n\n## Impact\n\n- **Session hijacking** — steal `PHPSESSID` cookie (not HttpOnly by default)\n- **Account takeover** — use stolen session to change password or email\n- **Phishing** — inject a realistic login form inside the SweetAlert modal\n- **Worm propagation** — inject self-spreading payloads via comments/messages\n- **Admin compromise** — send crafted link to admin, steal session, gain full control","status":"published","published":"2026-03-17T20:05:23Z","modified":"2026-03-20T21:22:26Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:39:39.567266Z"}],"nvd":[{"id":"CVE-2026-33035","description":"WWBN AVideo is an open source video platform. In versions 25.0 and below, there is a reflected XSS vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in a victim's browser. User input from a URL parameter flows through PHP's json_encode() into a JavaScript function that renders it via innerHTML, bypassing encoding and achieving full script execution. The vulnerability is caused by two issues working together: unescaped user input passed to JavaScript (videoNotFound.php), and innerHTML rendering HTML tags as executable DOM (script.js).  The attack can be escalated to steal session cookies, take over accounts, phish credentials via injected login forms, spread self-propagating payloads, and compromise admin accounts — all by exploiting the lack of proper input sanitization and cookie security (e.g., missing HttpOnly flag on PHPSESSID). The issue has been fixed in version 26.0.","status":"published","published":"2026-03-20T05:16:16.103Z","modified":"2026-06-17T10:36:50.607Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:10.126802Z"}],"osv":[{"id":"CVE-2026-33035","title":"Unauthenticated Reflected XSS via innerHTML in AVideo","description":"WWBN AVideo is an open source video platform. In versions 25.0 and below, there is a reflected XSS vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in a victim's browser. User input from a URL parameter flows through PHP's json_encode() into a JavaScript function that renders it via innerHTML, bypassing encoding and achieving full script execution. The vulnerability is caused by two issues working together: unescaped user input passed to JavaScript (videoNotFound.php), and innerHTML rendering HTML tags as executable DOM (script.js).  The attack can be escalated to steal session cookies, take over accounts, phish credentials via injected login forms, spread self-propagating payloads, and compromise admin accounts — all by exploiting the lack of proper input sanitization and cookie security (e.g., missing HttpOnly flag on PHPSESSID). The issue has been fixed in version 26.0.","status":"published","published":"2026-03-20T05:08:31.54Z","modified":"2026-10-28T02:31:14.415238576Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:01.548715Z"},{"id":"GHSA-wfq5-qgqp-hvhv","title":"Unauthenticated Reflected XSS via innerHTML in AVideo","description":"## Summary\n\nAVideo contains a reflected XSS vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in a victim's browser. User input from a URL parameter flows through PHP's `json_encode()` into a JavaScript function that renders it via `innerHTML`, bypassing encoding and achieving full script execution.\n\n\n## Root Cause\nThe vulnerability is caused by two issues working together:\n\n### 1. Source: Unescaped user input passed to JavaScript (videoNotFound.php)\n\n**File:** `view/videoNotFound.php` line 49\n\n```php\nif (!empty($_REQUEST['404ErrorMsg'])) {\n    echo 'avideoAlertInfo(' . json_encode($_REQUEST['404ErrorMsg']) . ');';\n}\n```\n\nPHP's `json_encode()` with default flags only escapes quotes (`\"` → `\\\"`) and backslashes. It does **NOT** escape HTML special characters (`\u003c`, `\u003e`, `/`). The resulting string contains raw HTML tags that are passed directly to JavaScript.\n\n### 2. Sink: innerHTML renders HTML tags as executable DOM (script.js)\n\n**File:** `view/js/script.js`\n\n```javascript\nfunction avideoAlertInfo(msg) {            // line ~1891\n    avideoAlert(\"\", msg, 'info');           // calls ↓\n}\n\nfunction avideoAlert(title, msg, type) {   // line ~1270\n    avideoAlertHTMLText(title, msg, type);  // calls ↓\n}\n\nfunction avideoAlertHTMLText(title, msg, type) {  // line ~1451\n    var span = document.createElement(\"span\");\n    span.innerHTML = msg;                  // line 1464 — XSS SINK\n    swal({ content: span });\n}\n```\n\n`innerHTML` parses the string as HTML. Any `\u003cimg\u003e`, `\u003csvg\u003e`, or other HTML tags with event handlers are instantiated as real DOM elements, triggering JavaScript execution.\n\n### Data Flow\n\n```\nURL parameter (?404ErrorMsg=PAYLOAD)\n    → $_REQUEST['404ErrorMsg']\n    → json_encode()          ← does NOT escape \u003c \u003e /\n    → avideoAlertInfo()\n    → avideoAlert()\n    → avideoAlertHTMLText()\n    → span.innerHTML = msg   ← renders HTML tags, executes JS\n```\n\n---\n\n## Proof of Concept\n```\nhttps://localhost/view/videoNotFound.php?404ErrorMsg=\u003cimg src=x onerror=alert(document.domain)\u003e\n```\n\u003cimg width=\"1918\" height=\"1035\" alt=\"image\" src=\"https://github.com/user-attachments/assets/20077ce2-5b49-4bd3-a7df-ab48be786cc1\" /\u003e\n\nThe page renders:\n```javascript\navideoAlertInfo(\"\u003cimg src=x onerror=alert(document.domain)\u003e\");\n```\n\nWhich flows to `span.innerHTML = \"\u003cimg src=x onerror=alert(document.domain)\u003e\"`. The browser creates an `\u003cimg\u003e` element, `src=x` fails to load, `onerror` fires `alert(document.domain)`.\n\n## Affected Code\n\n| File | Line | Issue |\n|------|------|-------|\n| `view/videoNotFound.php` | 49 | `json_encode()` does not escape `\u003c` `\u003e` for HTML context |\n| `view/js/script.js` | 1464 | `span.innerHTML = msg` renders user input as HTML |\n| `view/js/script.js` | 1282 | `span.innerHTML = msg` in `avideoAlertWithCookie()` |\n| `view/js/script.js` | 1335 | `span.innerHTML = __(msg,true)` in `avideoConfirm()` |\n| `view/js/script.js` | 1358 | `span.innerHTML = msg` in `avideoAlertOnceForceConfirm()` |\n\nThe `innerHTML` sink exists in 4 functions. Any future code that passes user input to `avideoAlertInfo()`, `avideoAlertWarning()`, `avideoAlertDanger()`, or `avideoAlertSuccess()` will create additional XSS vectors.\n\n\n## Remediation\n\n### Fix 1: Escape HTML in PHP (source fix)\n\n```php\n// view/videoNotFound.php line 49\n// BEFORE (vulnerable):\necho 'avideoAlertInfo(' . json_encode($_REQUEST['404ErrorMsg']) . ');';\n\n// AFTER (fixed):\necho 'avideoAlertInfo(' . json_encode($_REQUEST['404ErrorMsg'], JSON_HEX_TAG | JSON_HEX_AMP) . ');';\n```\n\n`JSON_HEX_TAG` converts `\u003c` → `\\u003C` and `\u003e` → `\\u003E`, preventing HTML injection.\n\n### Fix 2: Use textContent instead of innerHTML (sink fix, recommended)\n\n```javascript\n// view/js/script.js - all alert functions\n// BEFORE (vulnerable):\nspan.innerHTML = msg;\n\n// AFTER (fixed):\nspan.textContent = msg;\n```\n\n`textContent` treats the string as plain text — HTML tags are displayed literally, never parsed or executed.\n\n### Fix 3: Add Content-Security-Policy header (defense in depth)\n\n```\nContent-Security-Policy: default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'\n```\n\n## Impact\n\n- **Session hijacking** — steal `PHPSESSID` cookie (not HttpOnly by default)\n- **Account takeover** — use stolen session to change password or email\n- **Phishing** — inject a realistic login form inside the SweetAlert modal\n- **Worm propagation** — inject self-spreading payloads via comments/messages\n- **Admin compromise** — send crafted link to admin, steal session, gain full control","status":"published","published":"2026-03-17T20:05:23Z","modified":"2026-03-20T21:37:42.693809Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:46:58.401149Z"}]}}