CVE-2026-100718

What it is

Froxlor through 2.3.10 does not enforce the mail.allow_external_domains policy in the EmailSender.add API command. When an administrator has enabled the allowed-sender feature but disabled external allowed-sender domains (mail.enable_allow_sender = 1, mail.allow_external_domains = 0), an authenticated customer with API access can still use EmailSender.add to register an arbitrary external sender address for their mailbox, which is stored despite the policy. This creates a bypass between the UI/administrator configuration and the API, and — where the generated mail configuration consumes the allowed-sender table — allows a customer to authorize sender identities outside their hosted domains, facilitating sender spoofing. Fixed in 2.3.12.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data tampering.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-26 14:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-26 23:16 UTC Last updatedMost recent change to the record

Details

Published

2026-09-26 14:16 UTC

Last modified

2026-09-26 23:16 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-276 · Incorrect default permissions

Record status

Deferred

Attack profile CVSS 4.0 · 7.1

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

None

Confidentiality

Low

Integrity

High

Availability

None