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

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

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 May 2026
- **Updated:** 12 May 2026
- **Also known as:** GHSA-5hgj-7gm9-cff5

## 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 (Improper Verification of Source of a Communication Channel)

## Which versions are affected by CVE-2026-43880?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `wwbn/avideo` | Packagist | All versions to 29.0 | None |
| `wwbn/avideo` | Packagist | All versions to 29.0 | None |

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43880 and fix it if it is affected.

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

Affected packages and fixed versions:
- wwbn/avideo (Packagist): affected all versions up to 29.0; no fix listed
- wwbn/avideo (Packagist): affected all versions up to 29.0; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-43880/ (Markdown: https://insights.sbomify.com/CVE-2026-43880/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43880
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43880
- OSV: https://osv.dev/vulnerability/CVE-2026-43880

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43880/
Summaries are generated and may contain mistakes; the official description above is the record.