# CVE-2026-113599: Modoboa insecure direct object reference in auto-reply

Source: https://junglewise.ai/threats/cve-2026-113599-modoboa-before-2-8-0-contains-an-insecure-direct-object  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-113599 · Severity: medium · CVSS 5.4 · Published 2026-10-20

Modoboa is a mail server and webmail management platform. An authenticated user can exploit an insecure direct object reference vulnerability in the auto-reply API to inject malicious auto-reply messages for other users' mailboxes or disrupt their auto-reply settings, enabling account compromise and mail redirection attacks.

Technologies: [Modoboa](https://junglewise.ai/threats/technologies/modoboa). Vendors: [Modoboa](https://junglewise.ai/threats/vendors/modoboa).

## Quick answers

**Is CVE-2026-113599 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-113599 being exploited in the wild.

**How severe is CVE-2026-113599?** Medium severity, with a CVSS score of 5.4, published 20 October 2026.

**Which products and versions are affected?** Modoboa before 2.8.0.

**Is there a fix for CVE-2026-113599?** Yes: fixed in 2.8.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-113599 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-113599?** Check whether you run Modoboa 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 2.8.0

## Technical details

The ARMessageSerializer in the auto-reply API does not properly validate that the authenticated user owns the mailbox they are modifying. An attacker can POST to /api/v2/armessages/ with another user's mbox identifier to create or modify auto-reply messages, subject and content for arbitrary mailboxes. The lack of ownership checks on the mbox field allows privilege escalation within the application.

## Affected products

- Modoboa Modoboa before 2.8.0

## Timeline

- 2026-10-20: disclosed
- 2026-02-26: patched: Commit e0a4e3b fixes the issue per GitHub

## References

- [https://github.com/modoboa/modoboa/blob/2.7.2/modoboa/autoreply/api/v2/serializers.py](https://github.com/modoboa/modoboa/blob/2.7.2/modoboa/autoreply/api/v2/serializers.py)
- [https://github.com/modoboa/modoboa/commit/e0a4e3b9ee8ad84dba46e4c0f04cbbe7cf78c38d](https://github.com/modoboa/modoboa/commit/e0a4e3b9ee8ad84dba46e4c0f04cbbe7cf78c38d)

## Related threats

- [Modoboa insecure direct object reference in alarm deletion](https://junglewise.ai/threats/cve-2026-113598-modoboa-before-2-8-0-contains-an-insecure-direct-object)
- [Modoboa IDOR in account password change API](https://junglewise.ai/threats/cve-2026-56780-modoboa-idor-in-account-password-change-api)