Medium severityNVD Advisory· Published Oct 7, 2026

CVE-2026-33586

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.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

Ovh/OVH mail serversllm-create
Ovh/OVH email accountllm-create

Patches

Vulnerability mechanics

References

docs.ovhcloud.com/en/guides/web-cloud/email-and-collaborative-solutions/troubleshooting/email-rejected-cross-domain-spoofingnvd

News mentions

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