Authenticated users are able to manipulate both the SMTP envelope “Envelope-from” and “From” fields when sending emails through OVH mail servers. Due to OVH's default SPF configuration, which commonly includes include:mx.ovh.com, any authenticated user with a valid OVH email account can send messages that appear to originate from any OVH-hosted domains using the default SPF record. Since the SPF policy explicitly authorizes OVH mail servers (mx.ovh.com) to send mail on behalf of these domains, forged messages successfully pass SPF validation despite not being authorized by the impersonated domain owner.
History

Fri, 09 Oct 2026 09:15:00 +0000

Type Values Removed Values Added
First Time appeared Ovhcloud
Ovhcloud ovhcloud
Vendors & Products Ovhcloud
Ovhcloud ovhcloud

Wed, 07 Oct 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 07 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Description Authenticated users are able to manipulate both the SMTP envelope “Envelope-from” and “From” fields when sending emails through OVH mail servers. Due to OVH's default SPF configuration, which commonly includes include:mx.ovh.com, any authenticated user with a valid OVH email account can send messages that appear to originate from any OVH-hosted domains using the default SPF record. Since the SPF policy explicitly authorizes OVH mail servers (mx.ovh.com) to send mail on behalf of these domains, forged messages successfully pass SPF validation despite not being authorized by the impersonated domain owner.
Title Authenticated SMTP Sender Address Forgery
Weaknesses CWE-1188
CWE-290
CWE-346
References
Metrics cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N/E:A'}


cve-icon MITRE

Status: PUBLISHED

Assigner: ENISA

Published: 2026-10-07T15:00:14.278Z

Updated: 2026-10-07T20:27:49.038Z

Reserved: 2026-03-23T12:53:47.473Z

Link: CVE-2026-33586

cve-icon Vulnrichment

Updated: 2026-10-07T20:27:44.459Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-07T16:17:47.643

Modified: 2026-10-08T21:33:42.423

Link: CVE-2026-33586

cve-icon Redhat

No data.