CVE-2026-43880: WWBN AVideo is an open source video platform. In versions up to and including 29.0, objects/sendEmail.json.php exposes two branches depending on wheth...

Description

WWBN AVideo is an open source video platform. In versions up to and including 29.0, objects/sendEmail.json.php exposes two branches depending on whether contactForm=1 is submitted. When the parameter is omitted, the endpoint sets $sendTo to an attacker-supplied email and, for unauthenticated callers, uses the site's own contact email as the message From:/Reply-To:. The endpoint is explicitly allow-listed as a "public write action" in objects/functionsSecurity.php (line 885), so it requires no authentication or CSRF token. An unauthenticated attacker (solving a captcha) can force the site's own SMTP infrastructure to send attacker-composed emails to arbitrary recipients with the site's legitimate sender address, passing SPF/DKIM/DMARC for the site's domain — ideal for targeted phishing and brand impersonation. Commit 4e3709895857a5857f0edb46b0ee984de0d9e1a2 contains an updated fix.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

0.23%

13.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-940

References

Timeline

Published: May 11, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-43880?

WWBN AVideo is an open source video platform. In versions up to and including 29.0, objects/sendEmail.json.php exposes two branches depending on whether contactForm=1 is submitted. When the parameter is omitted, the endpoint sets $sendTo to an attacker-supplied email and, for unauthenticated callers, uses the site's own contact email as the message From:/Reply-To:. The endpoint is explicitly allow-listed as a "public write action" in objects/functionsSecurity.php (line 885), so it requires no authentication or CSRF token. An unauthenticated attacker (solving a captcha) can force the site's own SMTP infrastructure to send attacker-composed emails to arbitrary recipients with the site's legitimate sender address, passing SPF/DKIM/DMARC for the site's domain — ideal for targeted phishing and brand impersonation. Commit 4e3709895857a5857f0edb46b0ee984de0d9e1a2 contains an updated fix.

How severe is CVE-2026-43880?

CVE-2026-43880 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2026-43880?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.