# CVE-2026-120329: TYPO3 Mail extension arbitrary page TSconfig write

Source: https://junglewise.ai/threats/cve-2026-120329-saving-the-configuration-of-the-mail-backend-module-writes  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-03. Updated: 2026-11-03  
License: CC BY 4.0 with a link back

CVE-2026-120329 · Severity: info · Published 2026-11-03

The Mail extension for TYPO3, a popular web content management system, contains a vulnerability in its backend configuration module. An authenticated backend user with access to the mail module can write arbitrary page configuration settings (TSconfig) beyond what the module normally permits, potentially allowing them to alter site behavior or access sensitive data.

Vendors: [Typo3](https://junglewise.ai/threats/vendors/typo3).

## Quick answers

**Is CVE-2026-120329 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120329 being exploited in the wild.

**How severe is CVE-2026-120329?** Informational severity, published 3 November 2026.

**Which products and versions are affected?** Typo3 Mail extension 3.12.4 and below, 4.0.0 - 4.1.0.

**Is there a fix for CVE-2026-120329?** Yes: fixed in Mail extension 3.12.5 and 4.2.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-120329 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-120329?** Check whether you run Typo3 Mail extension at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Mail extension 3.12.5 and 4.2.0

## Technical details

The mail backend module fails to restrict submitted configuration parameters when writing to page TSconfig, allowing an authenticated backend user to inject arbitrary configuration keys. This is a broken access control vulnerability (CWE-862) reachable over the network from authenticated backend users with mail module access. An attacker gains the ability to modify page-level configuration outside the intended scope of the mail module.

## Affected products

- TYPO3 Mail extension 3.12.4 and below, 4.0.0 - 4.1.0

## Timeline

- 2026-11-03: disclosed

## References

- [https://packagist.org/](https://packagist.org/)
- [https://typo3.org/security/advisory/typo3-ext-sa-2026-037](https://typo3.org/security/advisory/typo3-ext-sa-2026-037)

## Related threats

- [TYPO3 Mail extension server-side request forgery](https://junglewise.ai/threats/cve-2026-120331-content-of-external-url-mails-their-stylesheets-and-images-to)