CVE-2026-43880 AVideo: Unauthenticated Arbitrary Email Sending via sendEmail.json.php Enables Phishing from the Site’s Legitimate From Address

Medium 5.3 Published Updated

Unauthenticated attackers can send arbitrary emails via the site's SMTP server, enabling phishing and brand impersonation by bypassing sender authentication checks.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-43880?

CVE-2026-43880 is a medium-severity vulnerability in WWBN AVideo, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-940

Which versions are affected by CVE-2026-43880?

2 open source packages ship an affected version, including wwbn/avideo.

PackageAffectedFixed in
wwbn/avideo PackagistAll versions to 29.0None
wwbn/avideo PackagistAll versions to 29.0None

How do I fix CVE-2026-43880?

No fix has been published for CVE-2026-43880 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-43880 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43880 exists.

Sources

Also known as GHSA-5hgj-7gm9-cff5.

Is CVE-2026-43880 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free