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CVE PROGRAM SOURCE RECORD6.3 Medium

CVE-2026-33586

Authenticated SMTP Sender Address Forgery

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

OVHcloud OVHcloud

Default version status: unaffected

  • 0 to < 2026-07-20affected

References