EUVD Vulnerability Catalog
EUVD-2026-94378
Severity: MEDIUM
Base Score: 6.3
CVSS Version: 4.0
Vulnerability 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.
CVSS Vector Analysis
Below is the complete, human-readable breakdown of the CVSS metric string: 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
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Attack Vector (AV): Network
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Attack Complexity (AC): Low
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Attack Requirements (AT): None
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Privileges Required (PR): Low
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User Interaction (UI): None
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Vulnerability Confidentiality Impact (VC): None
▪
Vulnerability Integrity Impact (VI): None
▪
Vulnerability Availability Impact (VA): None
▪
Subsequent Confidentiality Impact (SC): None
▪
Subsequent Integrity Impact (SI): High
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Subsequent Availability Impact (SA): None
▪
E: Adjacent
Affected Vendors & Systems
Vendor
OVHcloud
References & Advisory Links
Metadata Profile
Database Authority
European Union Agency for Cybersecurity (ENISA) EUVD
Assigner
ENISA
EPSS Probability
0
Known Aliases
GHSA-rpc3-43rh-hpm4
CVE-2026-33586
Published On
2026-10-07
Last Updated
2026-10-07