Description
SOGo before 5.12.13 contains an improper cryptographic signature verification vulnerability that allows remote attackers to replace a victim's contact S/MIME certificate by sending a spoofed multipart/signed message with a mismatched signature and an impersonated From address. Attackers can deliver a crafted CMS signedData object containing their own self-signed certificate, which SOGo's UIxMailView stores on the contact card without validating signature authenticity or certificate identity, enabling subsequent encrypted communications to be decrypted with the attacker's private key.
Published: 2026-11-12
Score: 7.1 High
EPSS: n/a
KEV: No
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Thu, 12 Nov 2026 16:00:00 +0000

Type Values Removed Values Added
Description SOGo before 5.12.13 contains an improper cryptographic signature verification vulnerability that allows remote attackers to replace a victim's contact S/MIME certificate by sending a spoofed multipart/signed message with a mismatched signature and an impersonated From address. Attackers can deliver a crafted CMS signedData object containing their own self-signed certificate, which SOGo's UIxMailView stores on the contact card without validating signature authenticity or certificate identity, enabling subsequent encrypted communications to be decrypted with the attacker's private key.
Title SOGo before 5.12.13 S/MIME Certificate Spoofing via UIxMailView
Weaknesses CWE-347
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-12T17:17:31.603Z

Reserved: 2026-11-12T15:30:07.716Z

Link: CVE-2026-127121

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-12T16:19:07.587

Modified: 2026-11-12T18:17:41.600

Link: CVE-2026-127121

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-347

    Improper Verification of Cryptographic Signature