CVEvulnerability

CVE-2026-33586

6.3 MEDIUM Published 2026-10-07 Modified 2026-10-08 Official page ↗
Status
Awaiting Analysis
Published
2026-10-07
Last modified
2026-10-08
Assigner
a6d3dc9e-0591-4a13-bce7-0f5b31ff6158
CVSS 4.0 (a6d3dc9e-0591-4a13-bce7-0f5b31ff6158)
6.3 MEDIUM — 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weaknesses
CWE-1188, CWE-290, CWE-346

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.

Related

Weakness · CWE (3)

  • CWE-1188 Initialization of a Resource with an Insecure Default weakness
  • CWE-290 Authentication Bypass by Spoofing weakness
  • CWE-346 Origin Validation Error weakness

References